Cambridge Technical Introductory Diploma in IT

(Unit 2 - LO1)

Understand where information is held globally and how it is transmitted.

 

Part - - -

Individually think about the number of organisations that hold information about you and the type of information that they hold. (For example NHS records: name, address, medical information and so forth.) Write the list in Word.

Then as a group, create a list of these organisations and the type of information that they hold. Is there one organisation other than school and the NHS that appears in everyone's list? Are there any surprises?

1.1 Holders of information

Categories of holders

As a pair, create a table listing the different types of holders of information. (Develop this from the list created earlier.)

Individuals hold information about themselves, personal data such as their full name and date of birth. They may hold similar data about others such as phone numbers and email addresses in contact lists. They may hold information about organisations with which they have no direct contact. This information may have been passed to third parties, read on the internet or in books or even may have been stolen.

Business organisations hold much the same information as individuals, for examples dates of birth of employees. They will also hold commercial information about competitors, financial information about their own business and general information about relevant markets.

Government and healthcare services vast quantities of data about us. Every year employers pass on information about how much we have earned and the tax we have paid (actually the tax is deducted by the employer before we are paid and then they pay the Inland Revenue). The electoral roll holds information about people such as the address of all those who have registered to vote. Healthcare services hold information about our health and any necessary treatment. The government or one of its many agencies may hold information that has been gathered through various investigations that have yet to be published. Investigations could include police investigations or investigations into tax affairs or a public inquiry.

The government holds information about other governments too and where necessary (in its own opinion) may share this information with the public. (Interestingly when governments share information with each other a department checked to see if the other governments told the truth by comparing it to information it sourced openly from web sites that the other governments maintained and indeed they either lied to their own public or to their fellow governments.) The foreign office offers travel advice based on intelligence gathered from other countries.

Charities and community organisations also hold information, for example charities will have bank account details of their donors and a community organisation will hold the contact details of all of its members.

When you join an online community such as a bookface group, again the information is shared with other members and possibly others besides. Signing up to a commercial website so you can buy their products usually will involve giving them your contact and bank details which they are required to protect.

Location of information

  • - Developing vs. developed countries; developing countries tend to have a less developed industrial base than developed countries. Their "human development index". Alongside the less developed industrial base these "less developed", poorer nations tend to have less access to computers and the Internet. This therefore means that information dispersal and gathering is harder than for developed countries. That said it is possible for less developed nations to miss out some of the steps when modernising which may save on rfeduced investment in infrastructure. For example, Kenya had telephone loines in cities but the wired network did not spread to its more remote rural areas. However the introduction of wireless communicatkion has meant that the vast cost of upgrading twice has been omitted.
  • - Urban vs rural; even in developed nations, rural environments tend to have lower rates of access or slower speed of access than urban areas. This too makes information dispersal and gathering more difficult in riral areas.

The global divide

Access to the Internet is not spread evenly across the glode and this inequality is the focus of the global divide. it impacts a range of human endeavour; education, tourism and democracy are but three.

As individuals, select a country each and research the availability of broadband and other access issues in these countries:

  • - Afghanistan
  • - Saudi Arabia
  • - Australia
  • - Belgium
  • - Canada
  • - Denmark
  • - South Africa
  • - China

See the contributions here

Rank this list of nations:

  • - Afghanistan
  • - Saudi Arabia
  • - Australia
  • - Belgium
  • - Canada
  • - Denmark
  • - South Africa
  • - China

in terms of the access of their people to the Internet, least access to most access (in your own opinion).

1.2 Types of information (by media type)

Information can be held on or in:

Paper

Easy to use; traditional form of storage of data; varies from hand written notes, maps, books, legal documents; historic documents.

Easily damaged, expensive to transport; hard to keep securely and safely (degrades slowly over time); vulnerable to environmental conditions; bulky (when compared to other media) complex to encrypt safely.

Magnetic media

Magnetic media uses magnetic patterns to store data; began as tape, then disks then hard drives; tapes still used for backup; probably the most common form of electronic data storage; data density of a disk varies based on the physical location of the data; compared to previous technologies it is easily portable and relatively inexpensive.

Optical media

CD, DVD; usually stores music and film; storage and transmission media for software and data. can be encrypted; can be infected (The Concept virus was acid en tally added to a Microsoft CD - it became the most widespread virus then known in only a few days.); high data density; data density varies based on the physical location of the data; easily portable; initially quite expensive but the cost is now decreasing. Optical media can be encrypted but sometimes isn't when it should have been (Famous data breach and here.)

Solid state media

Storing information is circuitry rather than on disk or tape; SSD card in a camera now has huge capacity; small size and getting smaller; high constant data density; beginning to replace magnetic media; does not get hot; very small size makes it easily portable. It is still relatively expensive and can be encrypted easily (safe transmission of data through public means) although it frequently isn't.

1.2 Characteristics

Different forms of storage media have different characteristics.

  • Mutability – the ability to change the content of the storage medium. Some devices especially CDs and DVDs are read-only and cannot be edited. Other devices and paper can be read-write and can be repeatedly re-used.
  • Robustness – solid state media, because it has no moving parts is less likely to be damaged if dropped and so is often used in portable devices (not that they should be dropped!) while hard drives which rely on rapidly spinning internal discs as the storage medium are frequently damaged if dropped. IF magnetic media are held near a source of magnetism then the data can become inaccessible.
  • Access to data – tape storage has to be searched from the very beginning to find the files that are sought whereas a hard drive can access the required data in almost a single revolution of the disk pack. Thus tape systems can store large amounts of data (although some multi-terabyte drives are now available at reasonable cost) the access system is quite slow (compared to a hard drive or SSD). Tape systems are now only used for external back-up.
  • Cost – paper is relatively cheap but the costs of sending large amounts of paper-based information (such as books or complex reports) by post or by courier become prohibitive because of their weight. Hard drives have the highest data density and higher capacity than SSD but hybrid systems (a combined HD for space and an SSD for speed) are now available.
  • Storage capacity – this is the amount of data that can be stored on each device. As miniaturisation has progressed, so more data can be stored in the same physical space. At the time of writing a 10tb hard disk is available to consumers as is a massive 84Tb SSD from Samsung but at a huge cost.

The purpose of data storage

Fundamentally it is the permanent or temporary recording or archiving of data ready for processing at the time or at some point in the future. Different media have gained different purposes over time; for example tape drives are used almost exclusively for back-up and archive activities and not for day-to-day storage. CD and DVD are the media of choice for transferring and installing software. The fundamental purpose of storage media is to store information. Once this purpose has been accepted then issues such as how easily the information needs to be accessed for the given purpose become important. For example the relative difficulty of accessing information held on tape makes it unsuitable for general day-to-day storage. Additionally many new computers are being fitted with hybrid drives that have a single apparent drive letter but can combine the best of both HD and SSD technologies to provide high capacity (HD) and high speed (SSD).

Advantages and disadvantages

Different storage media have different advantages and disadvantages which will impact on the choice of media. The robustness of solid state media makes them extremely useful in devices that are likely to be dropped such as phones and tablets. The concomitant limitation is that their relative cost means that storage capacity is reduced; a typical tablet will have 64Gb whereas a similarly priced laptop will gave 500GB or even 1Tb. As desktop PCs and laptops are less likely to be to be dropped magnetic data storage which is less expensive than SSD are more liekly to be used. The relative cheapness of the stortage medium is then reflected in the price. The relative cheapness of CDs means that these are rapidly becoming a throw-away storage device. For example, many people will chose to make a CD copy of a music CD to play in the car which can then be replaced from the original if and when it ceases to be playable.

Media Advantages Disadvantages
Paper    
Magnetic tape    
Magnetic disk    
Optical disk    
Solid state    

You have 5 minutes to find what you think is the best Internet map that you can find. You can't use any that I have already found.

1.3 Types of information access and storage devices

Handheld devices

Hand hel devices can be held in the hand or worn - see wearable technology. Examples include smartphones (mobile phones which include aspects of computer functionality including Internet access), smart watches such as iWatch or FitBit, eBook readers (used to read digital versions of books such as the Kindle and small tablets such as the iPad.

Portable devices

Portable devices can be easily transported. Laptops are computers that only differ from desktop machines because of their portability while tablets are as portable as laptops but typically have less processing power. Most if not all tablets have solid state drives that are much smaller, have higher access speeds and consume less power than normal disk drives but are much more expensive and have a lower capacity. The processing power limitations of portable and tablet devices are reducing with each new generation of mobile centric processors

Fixed devices

Fixed devices are not meant to be portable. They include desktop computers which may be considered the traditional form of computer (we are talking PC here beginning in 1975 with the Altair 8800 – although the computer as an electronic device running a stored program goes back to the “Baby” built in Manchester in 1948 based on the earlier work of Turing and von Neumann), smart TVs which are televisions that include aspects of computer functionality  and games consoles which are specialised computers designed primarily for playing games.

Shared devices

Shared devices may be accessed by more than one user at a time. For example, a database server is a computer that runs and provides database services to other cmoputers. Data centres are usually commercial operations that provide access to the Internet and a non-stop Internet presence for client who would not otherwise be able to afford it while cloud storage applications such as DropBox allows users to store and share data on the Internet.

Characteristics and purpose

Many of the characteristics of information access and storage devices are the same as those described in LO1 1.2

Other characteristics include the following

  • Processing power [the amount of calculations per second]. The current record (at the time of writing) is the Sunway TaihuLight installed at the National Supercomputing Centre in Wuxi capable of 93 petaflops or 93,000 trillion calculations per second. It does use over 10 million cores to reach this astounding performance.  https://www.top500.org/lists/2016/11/ A typical i7 PC runs at about 50 Gigaflops.
  • Versatility is the ability of a device to complete different tasks. This is where games consoles typically suffer  as they are designed to play games and little else, although they are becoming more versatile over time by offering the services more traditionally provided by desktop PCs.

Storage capacity is the amount of data that can be stored on the device. Desktop PCs have had larger hard disk drives capable of terabytes  of storage whereas a tablet will have a much faster but far smaller 32 gigabytes of storage.

Information access and storage devices can have different purposes. The main focus of a games console is clearly playing video games. Desktop and laptop computers are powerful devices with relatively high processing power and so may be used as media devices as well as games computers or supporting office operations or as personal computers. On the other hand portable devices are used where significant processing power is not required such as web-based games playing reading books and Internet access rather than complex data intensive tasks such as data processing.

Advantages and disadvantages

Advantages and disadvantages relate to the functionality and characteristics of each device. For example a portable device can be used anywhere but may not offer sufficient power, while a high power desktop is limited to a single location so would be unsuitable to someone who worked regularly away from the office.

Activity

In groups research the advantages and disadvantages of each of the storage devices described LO1.3

Device Characteristics Purpose Advantages Disadvantages
Handheld        
Portable        
Fixed        
Shared        

Explain the information as a presentation.

1.4 The Internet

The precursor to the Internet was jumpstarted in the early days of computing history, in 1969 with the U.S. Defense Department's Advanced Research Projects Agency Network (ARPANET). ARPA-funded researchers developed many of the protocols used for Internet communication today.

Originally based on text and a few images the Internet now also conveys information in the form of videos and sound fles and many other forms of information.

The Internet (September 1968) is distinct from the Web (1990). What is a network? In tenet actually means Internetwork and comes from the fact that the Internet is a group of networks that have been networked together.

A network of interconnected networks spanning the wolrd.

Networks are made when computers and other devices are connected together. Most organisations organise their computers together to form a network and have a single poiont of access to the Internet. Therefore the Internet may be considered to be a number of networks, each joined to other networks. Due to the global spread of computer technology, this may be considered a worldwide network of computers. The Internet of Things is spreading the idea even further.

This is a 2005 map of the Internet. A clear map but significantly out of date.

Partial map of the Internet based on the Jan. 15, 2005, data found on opte.org. Each line is drawn between two nodes, representing two IP addresses. The length of the lines are indicative of the delay between those two nodes. Credit: Creative Commons The Opte Project (This is also rather out of date but I hope you get the idea?)

This is a map shows the Tweets about the sunset as the shadow crosses the earth. It shows a snippet of about 4 hours as a loop.

This is a more up-to-date map of the Internet, although it created some controversy from people in Canada. can you work out why and why they were wrong?

Here is a link to a 2012 map of the Internet; still out of date...

Kaspersky. Live Internet Threat Map

Here is a link to the complete map.

Digital Attack Map. Internet Threat Map

Internet connections

Types of connection

Connections to the Internet an be made different ways; for example, copper cable is based on the electrical conductivity of copper and is still the most popular form of connectivity due to lits low cost. Optical fibre uses strands of glass or plastic instead of copper and data is transferred as pulses of light rather than electical charges.

Group activity: research four of the following methods of Internet access.

  • - Dial-up
  • - Broadband
  • - Fixed broadband
  • - Fixed wireless
  • - Satellite
  • - Wireless hotspots
  • - Mobile phones

1.5 World wide web (www) technologies.

Types of www technology networks.

Although they are closely linked, the Internet and world wide web (www or web) are not the same thing. The Internet is a global network of connected computers. Teh www is formed by the web pages onteh Internet - the Internet being used to access the web. When it was developed, the web used 3 main technologies to ensure that it could be accessed by all the computers connected to the Internet - the hypertext transfer protocol (http) URL (uniform resource locator) and TCP/IP (transfer control protocol . Internet protocol). Together they create www technologies such as intranets and extranets.

One of the principles of the world wide web was Tim Berners-Lee's insistance that the www should be based on cross-platform, open source software.

You have ben asked to write a short article explaining how the growth and success of the www was affected by the use of cross-platform, open source software.

Research the terms "cross-platform" and "open source".

Write a short magazine article explaining the impact of these decisions.

1.6 Information formats

Explore and comment on all of the following seven formats. (This is not a trivial task; I am expecting about half a page for each topic. Each start with different formats so that all of the formats have been covered by at least two students by the end of the lesson. Please do not collude at this point, I am hoping that you will each find different and interesting material to discuss on Tuesday.

 

Web pages

Web pages are the fundamental information format on the Internet. As we know then can be static or dynamic. A dynamic page is constructed by the server based on the coded input of the viewer and can be different for each new viewer every time it is opened. A dynamic page is built afresh when ever it is loaded, based on the code stored on the web-server. The video outlines some of he major differences between the two types of site.

Whether you’ve come across these terms online or have heard it thrown around by your web designer, it is important to know the difference so that you can determine the best solution for your website.

Static Websites

A static site is a website that is written entirely using HTML. Each web page is a separate document and there are no databases or external files that are drawn upon.

This means that the only way to edit this type of website is to go into each page and edit the HTML. So you would have to do it yourself using a web page editor such as FrontPage or Dreamweaver, or pay your web developer to make updates for you.

Dynamic Websites

A dynamic website is written using more complex code — such as PHPor ASP — and has a greater degree of functionality. For instance, many dynamic websites can be controlled by a content management system. This means that you will potentially be able to make updates without needing any knowledge of HTML or any website software.

Each page of a dynamic website is generated from information stored in a database or external file. And the content management system that you may use to maintain your website directly modifies this stored information.

Which Should You Choose?

Many people prefer dynamic websites because they have a lot of benefits. Dynamic sites reduce ongoing maintenance costs, make data management very efficient, and enable the addition of any future addons such as data feeds or a comprehensive site search. They also make it impossible to destroy the layout, as might happen if you edit it from a web page editor.

There are some drawbacks to using dynamic websites. First, they usually cost more to develop, because they require more complex coding, as well as the development of a content management interface to enable you to maintain your website. Second, you will need to obtain web hosting which supports databases and dynamic languages. Fortunately, most hosts do offer these features by default.

If you realize that you do want a dynamic website which will enable you to maintain your own content, you can save costs by opting for a website that is only partly dynamic. For example, certain pages such as ‘About Us’ or ‘Contact Us’ pages can be static, whereas galleries or product catalogues can be dynamic. Also, consider opting for an open sourceCMS.

To determine which is best for your website, also consider asking your web developer for their opinion on which would be best.

Alternatively there is this:

Web Design Choices

Static v Dynamic Website Design

There are basically two main types of website - static and dynamic.
A static site is one that is usually written in plain HTML and what is in the code of the page is what is displayed to the user.

A dynamic site is one that is written using a server-side scripting language such as PHP, ASP, JSP, or Coldfusion. In such a site the content is called in by the scripting language from other files or from a database depending on actions taken by the user.

Relative merits of static and dynamic websites

Static sites - advantages

Flexibility is the main advantage of a static site - every page can be different if desired, to match the layout to different content, and the designer is free to put in any special effects that a client may ask for in a unique way on different pages. This allows theming - for instance an author may want a different theme for a different book and associated pages or perhaps for a series of books, in order to match the cover designs or the context of the stories.

Cost is generally lower up-front than a dynamic site.

Static sites - disadvantages

The main problem with any static site appears when you wish to update the content. Unless you are conversant with HTML and the design methods used in the site then you have to go back to the designer to have any content changes made. This may be perfectly ok when a new page is required which needs design input, but if all you want to do is change some text then it can be a nuisance for both client and designer.

The second main problem is scalability. If you wish to sell products on your site and you have a lot of them then you may have to construct individual pages for each one, which can take considerable time, effort and cost.

Costs - there are ongoing costs for updating the content.

Dynamic sites - advantages

The main advantages of dynamic sites are that by connecting them to databases you can easily pull in information in an organised and structured way to create product pages or categories of related products sorted in a variety of different ways depending on how the user wants to view them.

This ability to connect to a database means that you can also create a content management system - an interface which allows the client to input and manage data via a web-based series of administration pages. That content can be text for their pages and images to go along with the text, or items in their product range with categories, specifications, short and long descriptions, images, etc. In both these cases it can be as simple or as complex as the client requires.

There are little or no ongoing costs unless there is a change in the basic design or an extra capability added.

Dynamic sites - disadvantages

The design of a dynamic site is more fixed than a static one because many of the pages are essentially a template into which data and content is poured to create multiple pages of a similar type. So for instance all your product pages will be essentially the same page layout with different data being displayed. While some customisation cabability can be built in it is usually quite limited, such a selecting from a set of pre-defined options. Individual layout changes to particular pages are not usually possible.

Costs are higher initially than for a static site, and additional functionality may also cost more, particularly if it's something that wasn't envisaged originally and requires re-writing of the core code or database.

Blogs

"Weblogs" began as personal diaries documenting a blogger daily life. They are now much more diverse and used by businesses as well as individuals.

Podcasts

A podcast is ether a sound or video file that can be downloaded or played online. Frequently used for episodic programmes and almost essential listening for academic study.

Streamed audio and video

Usually used for television transmission over the Internet; such use requires above average bandwidth to be successful.

Social media channels

Sites that allow their users to interact socially even though they may be disparate geographically.

Document stores

Cloud storage about which there is a huge amount written.

RSS feeds

An RSS feed sends small snippets of information

Feedwind widget - BBC News feed


Criteria

Purpose

The purpose of each format should be obvious

Accessibility

How can each format be accessed? How does the access vary from format to format?

1.7 Advantages

For individuals

 

For organisations

 

1.8 Disadvantages

For individuals

 

For organisations

 

  • 1. Compare the characteristics of digital and optical media.
  • 2. What is meant by the term "mutability"?
  • 3. Identify one similarity and one difference between an intranet and an extranet.
  • 4. "The Internet is everyone connected to everyone else." Explain this statement.
  • 5. Describe two advantages and one disadvantage to an organisation of using the Internet to distribute data.