The Internet is a massive network of networks, a networking infrastructure. It connects millions of computers together globally, forming a network in which any computer can communicate with any other computer as long as they are both connected to the Internet. Information that travels over the Internet does so via a variety of languages known as protocols.
History of The Internet
The history of the Internet starts in the 1950s and 1960s with the development of computers. This began with point-to-point communication between mainframe computers and terminals, expanded to point-to-point connections between computers and then early research into packet switching. Packet switched networks such as ARPANET, were developed in the late 1960s and early 1970s using a variety of protocols. The ARPANET in particular led to the development of protocols for internetworking, where multiple separate networks could be joined together into a network of networks.
In 1982 the Internet Protocol Suite (TCP/IP) was standardized and the concept of a world-wide network of fully interconnected TCP/IP networks called the Internet was introduced. Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) developed the Computer Science Network (CSNET) and again in 1986 when NSFNET provided access to super computer sites in the United States from research and education organizations. Commercial internet service providers (ISPs) began to emerge in the late 1980s and 1990s. The ARPANET was decommissioned in 1990. The Internet was commercialized in 1995 when NSFNET was decommissioned, removing the last restrictions on the use of the Internet to carry commercial traffic.
Since the mid-1990s the Internet has had a drastic impact on culture and commerce, including the rise of near instant communication by electronic mail, instant messaging, Voice over Internet Protocol(VoIP) "phone calls", two-way interactive video calls, and the World Wide Web with its discussion forums, blogs, social networking, and online shopping sites.
The Seven Layers of The OSI Model:
The OSI, or Open System Interconnection, model defines a networking framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, and proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.
- Physical
- Data Link
- Network
- Transport
- Session
- Presentation
- Application
HTML
Short for Hypertext Markup Language, the authoring language used to create documents on the World Wide Web. HTML is similar to SGML, although it is not a strict subset.
HTML defines the structure and layout of a Web document by using a variety of tags and attributes. The correct structure for an HTML document starts with <HTML><HEAD>(enter here what document is about)<BODY> and ends with </BODY></HTML>. All the information you'd like to include in your Web page fits in between the <BODY> and </BODY> tags.
There are hundreds of other tags used to format and layout the information in a Web page. Tags are also used to specify hypertext links. These allow Web developers to direct users to other Web pages with only a click of the mouse on either an image or word(s). For a more complete list of tags, check out some of the URLs below.
World Wide Web
The World Wide Web, or simply Web, is a way of accessing information over the medium of the Internet. It is an information-sharing model that is built on top of the Internet. The Web uses the HTTP protocol, only one of the languages spoken over the Internet, to transmit data. Web services, which use HTTP to allow applications to communicate in order to exchange business logic, use the the Web to share information. The Web also utilizes browsers, such as Internet Explorer or Firefox, to access Web documents called Web pages that are linked to each other via hyperlinks. Web documents also contain graphics, sounds, text and video.
How The Internet Works
- Transport Control Protocol (TCP) – A protocol that operates at the transport layer and is used in combination with IP by most internet applications.
- Backbone – Refers to the principal data routes between large, strategically interconnected networks and core routes in the internet.
- Uniform Resource Locator (URL) – An assigned address on the internet for each computer.
Internet Connection
- LAN servers: Local servers can provide can provide access to the internet through normal connections.
- Serial-Line Internet Protocol (SLIP) and Point-to-point Protocol (PPP): Communications protocol software that transmits packets over telephone lines, allowing dial-up access to the internet.
- Connection via an On-line Service Provider (ISP): These services usually require sign-up procedures. Examples are America Online and Microsoft Network.
Phishing And Spoofing:
Phishing is the act of sending an e-mail to a user falsely claiming to be an established legitimate enterprise in an attempt to scam the user into surrendering private information that will be used for identity theft. The e-mail directs the user to visit a Web site where they are asked to update personal information, such as passwords and credit card, social security, and bank account numbers, that the legitimate organization already has. The Web site, however, is bogus and set up only to steal the users information.
Spoofing is forging an e-mail header to make it appear as if it came from somewhere or someone other than the actual source. The main protocol that is used when sending e-mail -- SMTP -- does not include a way to authenticate. There is an SMTP service extension (RFC 2554) that allows an SMTP client to negotiate a security level with a mail server. But if this precaution is not taken anyone with the know-how can connect to the server and use it to send spoofed messages by altering the header information.
Avoiding Scams
What to do
- Know who you are dealing with
- Understand that wiring money is sending like cash
- Read your monthly statements
What not to do
- Don’t send money to someone you do not know
- Don’t agree to deposit a cheque and wire money back
- Don’t reply to messages asking for personal or financial information
- Don’t play a foreign lottery
Virus Protection
Virus protection software is designed to prevent viruses, worms and Trojan horses from getting onto a computer as well as remove any malicious software code that has already infected a computer.
Most virus protection utilities now bundle anti-spyware and anti-malware capabilities to go along with anti-virus protection. Internet security suites go a step further by including additional capabilities like anti-spam, anti-phishing, firewall, file protection and PC optimization.
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