Web Technology and Multimedia key terms

?

World Wide Web (WWW)

World Wide Web:

  • collection of information that has grown up on computers connected to the internet , made available for anyone to access.
  • the information is made up of webpages
  • pages written using html
  • viewed using a web browser
  • contains HYPERTEXT ,provides clickable links to other pages
  • contains sound, video ,animation, graphics & text
  • Hyper Text Transfer Protocol used to send pages over internet
  • WWW is a multimedia serivce, URL of pages begins with http:// idicating the page uses the Hypertext Transfer Protocol
1 of 8

The Internet, URL, HTTP

The internet:

  • network of computers, each communicating with several other computers in the network but not with all of them.
  • world-wide communication system linking computers in geographically seperate locations through telephone lines and satelitles

URL(uniform resource locator):

  • reference to the address of a resource on the internet, e.g. http://www.ccea.org.uk

HTTP(hypertext transfer protocol):

  • application protocol used on the world wide web, defines how data is structured and transmitted
  • specifies how browsers and web servers should act in response to requests
2 of 8

IP address

IP address:

  • represents a standard set of rules used to ensure the proper transfer of infromation between computers on the internet
  • defines how date is to be structured and what control signals are used
  • every device using the TCP/IP protocol on a network has a unique IP address
  • IP address allows messages and data to be routed to the correct address on the network
  • IPv4 addresses consist of four numbers separated by a DOT(.) each number can range from 0 to 255 e.g. 123.0.0.215

IP addresses can be:

  • static - a permanent IP address doesnt change
  • Dynamic - temporary addresses that are assigned each time a computer accesses the internet
3 of 8

Web Browser & Web Server

Web Browser:

  • allows users to view and use web pages on the internet
  • responsible for requesting the text and graphics of web pages from servers on the Internet for display
  • usually in HTML format
  • can be used to view any HTML pages if users are online or offline

Web Server:

  • designed to deliver webpages across the internet or within the intranet
  • oricesses requests for infromation that comes from the internet infrastructure
  • contains application software to enable the transmission of content
  • uses client-server technology

client server technology: program that accesses the application is called the client e.g. browser. progam that provides the application is called the server.

4 of 8

Web Hosting & FTP

Web hosting:

  • web hosting service is required to have an internet presence
  • provides individuals and organisations with access to a web server and web space to store a website or webpages.
  • web host company will ensure that the website is available online and the service inclues; web space, e-mail service, online management interface , customer support.

FTP (File Transfer Protocol):

  • most common protocol used to transfer files across the internet between client and server devises. 
5 of 8

ISP

ISP (Internet Service Provider):

  • directly linked to the internet and acceots transmission from users over communications lines and onto the internet.
  • ISP sells internet access to companies or individuals
  • provides access to web servers which connect to search engines on the internet.

Services Provided by the ISP:

  • email service
  • bandwidth options
  • security features
  • customer support
  • website filtering
  • telephone or DTV package
6 of 8

Search Engine

Search Engine

  • 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 uses a webcrawler.
  • a webcrawlwer crwals through the web and constructs an index of pages
  • different search engines will search different servers to give different results

Meta Tags

  • used to specify key words in the heading of a HTML page.
  • these words help search engines categorise pages and decided wether or not to include them in search results
7 of 8

Cookies & Cache

Cache

  • temporary internet files allow to download website images , data and documents for faster viewing in the future.
  • a local copy of the document is kept so the browser will be able to load some of the information from each page visited without downloading the information again from the server 
  • thus decreasing the time it takes to load a webpage.

Cookies

8 of 8

Comments

No comments have yet been made

Similar ICT resources:

See all ICT resources »See all Systems and Software resources »