8) The Internet Service: The World Wide Web

Internet - a global information network, which has a single address space based on the protocol TCP / IP. The Internet consists of a number of services. Internet is often equated with WWW (World Wide Web - the World Wide Web), but it is only one, albeit the most well-known service (service).

WWW (World Wide Web - the World Wide Web) - the best known, most popular and widespread service Internet , means of obtaining information.

Technology WWW or simply Web, was developed in 1989 in Geneva, particle physics laboratory of the European Centre for Nuclear Research (CERN), and was originally aimed at creating a unified network for scientists engaged in high-energy physics.

Soon, however, this technology has much wider application and 1992. Web-service - it is a public most dynamic and rapidly growing online service.

  Web-Service based on two protocols

HyperText Transport Protocol (HTTP) - HyperText Transfer Protocol.

HyperText Markup Language (HTML) - Building Language Hypertext.

The concept of hypertext has long been known that a text document file format, except that the text itself can contain hypertext links to other documents, which can go directly to those documents.

Web-hypertext document may include text, 2D and 3D graphics, sound, video, links to other hypertext documents, links to files in various formats

Internet Links - URL (Uniform Resource Locator), can point not only to Web-documents, but also on other services and information resources Internet: FTP, E-Mail

Web operates on a client-server. On the Internet, there are many Internet servers that on customers - Internet users return him hypertext document - an Internet site.

9)Searching for Websites

10)Websites: Designing WebPages

11)Data Security: How does a virus operate ?

A computer virus is a program that spreads malicious code by copying itself and infecting host computers. Although some viruses are latent, others can corrupt data or impede system performance. The term is specific, distinguished by how viruses are distributed (through downloads, email attachments, or removable media such as CDs, DVDs, or USB drives), but is often used as a catchall, much like the word “malware.” It should be noted that adware and spyware are actually not viruses as they do not have the same reproductive ability.

Many viruses attach themselves to legitimate executable files on a host computer that allow the virus to be loaded when the user opens the file. A virus generally will be activated when it is loaded into a computer’s memory, and then it may continue to spread its viral code into a number of other programs and files stored on the host computer. The computer’s programs may still continue to work normally, but also spread the virus’ code to other machines on the same network, or machines that use the same storage devices. Some viruses use polymorphic code to avoid detection by antivirus software, modifying their decryption modules so that the virus changes each time it infects a new host.