Digital Technology

Is the name given to the collection of information that has grown up on computers

connected to the Internet and which is made available for anyone to access. The

information is made up of webpages.

Features of Pages on the World Wide Web

• written using the programming language HTML

• viewed using a web browser

• can contain sound, video, animation, graphics and hypertext as well as simple text

Also known as ‘the net’. It is a network of computers, each communicating with several other computers in the network, but not with all of them. It is a world-wide communication system linking computers in geographically separate locations through the use of a variety of telecommunication links such as telephone lines and satellites.

Uniform Resource Locator – a URL is a reference to the address of a resource on the Internet. An example of a URL which addresses the CCEA website is:

http://www.ccea.org.uk.

Hypertext Transfer Protocol is an application protocol used on the world wide web. It defines how data is structured and transmitted and specifies how browsers and web servers should act in response to requests.

Internet Protocol address. This represents a standard set of rules used to ensure the proper transfer of information between computers on the Internet.

Every device linked to a is identified by a unique IP address.

This software allows users to view and use the web pages on the Internet. It is responsible for requesting the text and graphics of webpages from servers on the Internet, and assembling them for display. These are usually in HTML format. Web browsers can be used to view any HTML pages whether users are online or offline.

• A computer designed to deliver Internet webpages across the Internet or within an Intranet.
• It processes requests for information that comes from the Internet infrastructure.
• The web server contains application software to enable the transmission of content and makes use of client-server technology.

In client-server technology, the program that accesses the application is called the client. This could be the browser. The program that provides the application is called the server

In order to have an Internet presence a web hosting service is required. This service provides individuals and organisations with access to a web server and web space to store a website or webpages. The web host company will ensure that the website is available online

 The service may include: web space to store the website, an e-mail feature, an interface for managing the website online, customer support

File transfer protocol – is the most common protocol used to transfer files across the Internet between client and server devices

An Internet Service Provider – has direct links to the Internet and accepts transmission from users over communication lines and passes these onto the Internet. The ISP sells Internet access to companies or individuals and provides access to web servers which connect to the search engines on the internet.

An ISP will provide the user with a range of services.

aA variety of bandwidth options

aAn email service

aA security features such as anti-virus, protection against hacking, viruses, spyware

and identity theft.

aWeb hosting service which allows users to upload their own webpages

aCustomer support

aWebsite filtering which will filter out unsuitable content

aTelephone or Digital TV package.

A search engine is a web-based tool that searches for information using keywords or criteria. The search engine will return results as website links based on the criteria provided. Some search engines use a spider or webcrawler. This programme ‘crawls’

through the web and constructs an index of pages. When a user wants to search for a topic using the Internet, the index of topics, made by the webcrawler, is used. The webcrawler ensures that the index is up to date. Different search engines will search different servers to construct the index. This is why a search on Google may give different results to a search on Firefox.

Meta tags can be used to specify key words in the heading of the HTML page. These words help search engines to categorise pages and decide whether or not to include them in the results for a particular search.