1 New Terms New Term: Protocol: A protocol is nothing more than a set of rules. On the Internet, it is a set of rules computers use to communicate across networks. As long as everyone follows the rules, communication can occur freely New Term: Backbone: A backbone is nothing more than a major cable that carries network traffic. Although thousands of regional private and public networks exist, most Internet traffic spends most of its trip on one of the major backbones TCP/IP is a set of protocols developed to allow cooperating computers to share resources across a network. Today TCP/IP is the most important protocol that internet is based on. Dr. Loai Bani Melhim

2 The Primary Advantages of the TCP/IP 1. It is the most complete and accepted enterprise networking protocol available today. 2. All modern operating systems offer TCP/IP support. 3. Most large networks rely on TCP/IP for much of their network traffic. 4. TCP/IP is also the protocol standard for the Internet. 5. Using TCP/IP technology is the ability to connect dissimilar systems. Dr. Loai Bani Melhim

3 Some Common Terms The Internet is a network of computers spanning the globe. It is also called the World Wide Web. An Internet Browser is a software program that enables you to view Web pages on your computer. Browsers connect computers to the Internet, and allow people to “surf the Web.” Internet Explorer is one of the browsers most commonly used. There are other browsers available as well, including Netscape. Dr. Loai Bani Melhim

4 A site or area on the World Wide Web that is accessed by its own Internet address is called a Web site. A Web Page is like a page in a book. Websites often have several pages that you can access by clicking on links. A Web site can be a collection of related Web pages. Each Web site contains a home page (this is the original starting page) and may also contain additional pages. Different computers will have different home pages. You can set your own webpage. Dr. Loai Bani Melhim

5 Layout of a Web Page 1.Title bar – tells you the name of the web page 2.Menu bar – has commands for moving around the webpage, printing, etc 3.Tool bar – short cuts to commands. Each picture represents a command 4.Address bar – webpage address. If you want to go directly to a web page, you will need to know the address. Dr. Loai Bani Melhim

6 Parts of a Web Address A web address is typically composed of four parts: For example, the address is made up of the following areas: This Web server uses Hypertext Transfer Protocol (HTTP). This is the most common protocol on the Internet. www This site is on the World Wide Web. google The Web server and site maintainer. ca This tells us it is a site in Canada. Dr. Loai Bani Melhim

7 Endings of web pages tells us a bit about the page. Some common endings to web addresses are: com (commercial) edu (educational institution) gov (government) net (network) org (organization) You might also see addresses that add a country code as the last part of the address such as: ca (Canada) uk (United Kingdom) fr (France) us (United States of America) au (Australia) Dr. Loai Bani Melhim

8 How to Search the Internet Two basic ways 1. if you know the address of the web page (example: ) 2. Using a search engine like Google to find the address. This is called a keyword search Dr. Loai Bani Melhim

9 Typing in the Web Site Address 1. Go to the address bar. Click once to highlight the address. (It should turn blue). 2. Hit the Delete key on your keyboard. 3. Enter the following address: Then press Enter on the keyboard or click on the word Go on the right side of the Address Bar. Dr. Loai Bani Melhim

10 Search the Internet If you don’t know the address of the webpage, but want to learn more about a topic or find a particular website, you will need to do a search. There are several handy search engines out there that will locate information for you. Two of the mostly commonly used are: Dr. Loai Bani Melhim

11 Ways of Internet Utility 1. Communication 2. Remote File Transfer Operations 3. Web Publishing 4. Document Searching Dr. Loai Bani Melhim

12 Ways of Internet Utility With all the publicity and television commercials, you might conclude that the most popular use of the Internet is the World Wide Web. Well, here's a surprise. The most popular use, even today, is electronic mail, or . That's right, good old person-to-person, "let's talk"-type communication. It is almost fitting that one of the original uses of the Internet would still be the most popular. You can, of course, communicate in other ways on the Net. In the following sections, you look at a few ways people are using the Internet to communicate with one another. Dr. Loai Bani Melhim

13 Communication Personal Communication Why ? provides you with more than just a way to write Aunt Jane a note about how things are going. Of course, many people can and do use for this very task, and it is very effective when used this way. But you also can find some more practical reasons for personal communication. Have you ever tried to get in touch with someone and ended up playing phone tag for two days before finally getting hold of them? If you have, you know how frustrating this situation can be. Fortunately, e- mail eliminates this problem. Dr. Loai Bani Melhim

14 Communication Using , you can quite often get hold of people who might otherwise take hours or days to get in touch with. Not only that, but by using , you can contact them on your time--no more waiting on hold or wondering whether you've been disconnected. Just send some , go about your other business, and wait for a response to pop in your mailbox. Which, by the way, points to 's biggest advantage: It's fast! It's in the Mail Dr. Loai Bani Melhim

15 Communication Faxes are nice, but over long distances, the costs can add up. What if you had a quick and easy way to transmit instantly any type of file, document, or computer program electronically? Well, you do. With most programs, you can encode and "attach" documents to messages. Why bother with wasted paper and time at the fax machine? your message! Dr. Loai Bani Melhim

16 Communication A Public Forum Wouldn't it be great if you could have access to hundreds of other people through one address? The listserv is just such a vehicle. By signing up, or "subscribing," to a listserv, you then gain instant access to everyone else who subscribes to that listserv. Dr. Loai Bani Melhim

17 Communication A Public Forum New Term: Listserv: A listserv is basically an address that is configured to forward every message it receives to the addresses of the users who have "subscribed" to it. You can think of a listserv as an electronic interactive newspaper. Listservs have literally thousands of topics for their member to discuss. Everybody from programmers to zoologists can find a listserv. If more than one person is interested in a particular topic, you can almost certainly find a listserv for it. Dr. Loai Bani Melhim

18 Communication CAUTION: Listservs are great, no doubt about it. They do, however, pose a downside. Some of them are large and can sometimes dump hundreds of messages a day into your mailbox, so be careful out there. Dr. Loai Bani Melhim

19 Communication More Public Forums Using listservs isn't the only way to reach out and talk to large groups of people on the Internet. Using newsgroups, you can accomplish the same task in a different way. Dr. Loai Bani Melhim

20 Communication The differences between listserv and newsgroups The first difference between a listserv and a newsgroup is in the way messages are received. With listservs, messages are sent directly to your mailbox, where you have to sort them out and decide what to read. Newsgroup messages, on the other hand, are posted to something like a public electronic bulletin board, where you have to go to read the messages. Dr. Loai Bani Melhim

21 Communication The differences between listserv and newsgroups The second difference is one of access. Anybody with an address can subscribe to a listserv. To read newsgroups, however, your Internet service provider must provide you with access. Dr. Loai Bani Melhim

22 Communicate in Real Time In the last few years, the Internet has been hit by a wave of real-time communication. The processes of getting information, talking to others, and collaborating with colleagues no longer require a waiting period. Chatting At some point, you may want to remove the time delay between sending and receiving . You may want to converse directly with another person or have the ability to address a group of people. Today the most popular chatting services and tools are IRC and ICQ. Dr. Loai Bani Melhim

23 What Is IRC and How Does It Work? IRC (Internet Relay Chat) was developed in the late 1980s by Jarkko Oikarinen. It consists of a network of chat servers located all over the globe. Each server is connected via the network, allowing users to have real-time communications. Using IRC, large groups of people can simultaneously participate in discussion groups, called channels. A user's message is instantly viewed by all the other guests in that channel. Dr. Loai Bani Melhim

24 What Is IRC and How Does It Work? IRC poses no restrictions to the number of users. Tens of thousands of people connect to IRC everyday to discuss everything from world news to what they had for dinner last night. If you can't find a channel for your topic of discussion, you can always start your own. Actually, a few separate networks make up IRC. The two biggest are EFnet and Undernet. Some channels are shared by both, whereas other channels reside on only one of the networks. Because of the network connections to either EFnet or Undernet, you don't have to connect to the same server every time. Try connecting to the one that is geographically closest to you. Doing so may make your connection faster. Dr. Loai Bani Melhim

25 Remote File Transfer Operations FTP (File Transfer Protocol) is the one of the most important and popular protocols used in Internet. Any two computers from any two parts of the world can be connected to each other through FTP in order to send, get any file to/from each other. You can use standard FTP commands in order to connect to an FTP server, then you may upload (send) or download (get) any file to/from this server (if you familiar with the command set of FTP). If you do not know FTP commands, you may use any FTP tools (e.i.: Cute-FTP, Bulletproof- FTP) or a new generation web browser which is supporting FTP (e.i.: Internet explorer, Netscape Navigator, …) for this purpose. Dr. Loai Bani Melhim

26 Remote File Transfer Operations Most of the FTP servers require user accounts with passwords in order to allow their users to connect themselves. FTP servers may allow foreign users to login (connect themselves) as anonymous user with limited rights. Dr. Loai Bani Melhim

27 WEB Publishing World Wide Web (WWW) is going to be the most effective and the cheapest publishing environment of today (it is competing with TV now). Hyper Text Markup Language (HTML) is a language that forms the documents in order to published in the WWW environment. Hyper Text Transfer Protocol (HTTP) is a protocol, that is used for transferring HTML pages from WEB servers to the clients browsers. Dr. Loai Bani Melhim

28 Document Searching The Internet isn't called the Information Superhighway for nothing. The Internet is information. Sometimes unfiltered, many times even useless, more information is available on the Internet than any one person could ever deal with. Dr. Loai Bani Melhim

29 Document Searching Fortunately, some powerful search tools can help you find just about anything you want (i.e.: Finding People, Places, and Things). In the final analysis, whether you find the Internet useful depends to a large degree on whether you can find the information you want and need. Dr. Loai Bani Melhim

30 Document Searching New Term: Search engine: A search engine does exactly what its name says. It is really a computer program that indexes a database and then enables users to search it for relevant information. Finding Things You can search for billions of things on the Internet. Searching is an integral part of anyone's Internet use today. Dr. Loai Bani Melhim

31 What exactly is the web? The web is a complex, international, cross platform, cross language, cross cultural mesh of servers, clients, users, databases, and quite a few artificial intelligences all talking, working, searching, viewing, accessing, downloading, and who knows what else. Dr. Loai Bani Melhim

32 What exactly is the web? As such, no one owns or controls the web. In fact, it is impossible to own or control by its very nature and design. In fact, "it" is not even an "it". You can't hold the web or make it tangible. Instead, you can think of the web not as a thing, but as a process, an action, a medium of communication. This fact has profound implications on how you should think about designing web pages. For example, give up any hopes of maintaining intellectual property over what you distribute on the web and know that the only information that is private or secure is the information that is stored solely in your own neurons. Dr. Loai Bani Melhim

33 What exactly is the web? “The Internet" is quite a different thing from "an Intranet". An Intranet is a mini web that is limited to the users, machines, and software programs of a specific organization, usually a company. Since organizations are typically small and have more control over policies and information systems, intranets are often more controllable. Dr. Loai Bani Melhim

34 What exactly is the web? So how do all these computers, software packages, and people communicate with each other? The creators of the web devised standards of communication upon which the web is built. These standards sit at a layer above operating systems, computer languages, or Internet transmission protocols and provide a basic medium for communication. Dr. Loai Bani Melhim

35 What exactly is the web? The two most important standards (protocols) used on the web today are HTTP and HTML. Let's look at each of those protocols more in depth... The web is the largest client/server system implemented to date." It is also the most complex and heterogeneous one that must deal with multitudes of operating systems, human languages, programming languages, software, hardware, and middleware. Dr. Loai Bani Melhim

36 What is a client/server system? A client/server system is a very keen way of distributing information across information systems like a local area network (LAN), a wide area network (WAN), or the Internet. A client/server system works something like this: A big hunk of computer (called a server) sits in some office somewhere with a bunch of files that people might want access to. This computer runs a software package (uh...also called a server unfortunately) that listens all day long to requests over the wires. Dr. Loai Bani Melhim

37 What is a client/server system? The whole process looks something like the figure below: Dr. Loai Bani Melhim

38 What is a client/server system? So if the web is a huge client/server system, what is the underlying client/server protocol that is used by the client software and the server software for communication? Well the client/server protocol used by the web is HTTP (HyperText Transport Protocol). HTTP is a protocol that is defined in several RFC´s (Request for Comments) located at the Internic and has had several generations worth of revisions (HTTP/09, HTTP/1.0 and HTTP/1.1). Dr. Loai Bani Melhim

39 What is a client/server system? HTTP is a "request-response" type protocol that specifies that a client will open a connection to a server then send a request using a very specific format. The server will then respond and close the connection. The details of HTTP are less important for an HTML designer as they are to a web programmer, so we will not go into the specifics here (although they are available from the Illustrated Guide to HTTP referenced in the Resources section below). Dr. Loai Bani Melhim

40 What is a client/server system? The main thing you need to know is that HTTP is a language spoken between your web browser (client software) and a web server (server software) so that they can communicate with each other and exchange files. As a web designer, you will deal much more with the other web protocol, HTML that is discussed next. Dr. Loai Bani Melhim

41 HTML the Language of the Web So what does a web browser (client software) do with a file it receives from a web server (server software)? Does it just display it to the human user as is? The answer is yes and no. Actually, in some cases, the web browser will display a document exactly the way it receives it from the web server. For example, if the document requested is an image, the web browser will display it directly. Similarly, plain text files will be displayed just as they are sent. However, if the document is an HTML document, the web browser will "interpret" the HTML and display it according to the instructions contained within the HTML code. Dr. Loai Bani Melhim

42 HTML the Language of the Web Well, what is HTML code and why must it be interpreted? HTML (Hyper Text Markup Language) is a very simple language used to "describe" the logical structure of a document. Dr. Loai Bani Melhim

43 HTML the Language of the Web Is HTML a Programming Language? Actually, though HTML is often called a programming language it is really not. Programming languages are 'Turing-complete', or 'computable'. That is, programming languages can be used to compute something such as the square root of pi or some other such task. Typically programming languages use conditional branches and loops and operate on data contained in abstract data structures. HTML is much easier than all of that. HTML is simply a 'markup language' used to define a logical structure rather than compute anything. It is a semantic issue, but it is one which you should officially be aware of. Dr. Loai Bani Melhim

44 HTML the Language of the Web For example, it can describe which text the browser should emphasize, which text should be considered body text versus header text, and so forth. The beauty of HTML of course is that it is generic enough that it can be read and interpreted by a web browser running on any machine or operating system. This is because it only focuses on describing the logical nature of the document, not on the specific style. The web browser is responsible for adding style. For instance emphasized text might be bolded in one browser and italicized in another. It is up to the browser to decide. Dr. Loai Bani Melhim