Web programming lecture notes

Web programming lecture notes in Web Programming uploaded at P.R.Engineering college

Web programming lecture notes in Web Programming at P.R.Engineering college uploaded by P.R.Engineering college Staff in lecturenotes.net

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UNIT 1

Basic internet concepts-connecting to internet-Domain Name Space(DNS) - Exchanging e-mail-sending and receiving file-Fighting spam-Avoiding email Viruses-Chatting and conferencing on the internet-online chatting-messaging- Usenet newsgroup-Internet Relay Chat(IRC)-Instant Messaging-Voice and Video Conferencing.

1.1 BASIC INTERNET CONCEPTS

What is the Internet?

The Internet is a global collection of computer networks that are linked together by devices called routers and use a common set of protocols for data transmission known as TCP/IP (transmission control protocol / Internet protocol). The primary purpose of the Internet is to facilitate the sharing of information. There are many different tools used on the Internet to make this possible. Some of the more common tools include email, listservs, newsgroups, telnet, gopher, FTP, and the World Wide Web. Probably the most popular of all Internet tools is the World Wide Web.

The Internet is a network of computer networks. It makes it possible for any computer connected to it to send and receive data from any other computer connected to it.
America Online, Comcast, Earthlink, etc. are examples of Internet service providers. They make it physically possible for you to send and access data from the Internet. They allow you to send and receive data to and from their computers or routers which are connected to the Internet.

World Wide Web is an example of an information protocol/service that can be used to send and receive information over the Internet. It supports:

Multimedia Information (text, movies, pictures, sound, programs . . . ).

HyperText Information (information that contains links to other information resources).

Graphic User Interface (so users can point and click to request information instead of typing in text commands).

The World Wide Web is an example of an information protocol/service that works using a Client/Server software design. (Client/Server is an ADJECTIVE that describes the software, not a noun!) A service that uses Client/Server design requires two pieces of software to work: Client software which you use to request information, and Server software which an Information Provider (like Fermilab or a museum) uses to answer requests and provide their information. Most Internet information protocol/services are designed this way.

The Client/Server relationship is similar to the relationship between the TV in your  house and the TV stations you can select. Your TV acts as a client by tuning in (requesting

information) from a TV station which acts as a server by broadcasting (serving) the information.

This means that if you encounter an error while using your Web browser, this may be due to a problem with the Web server you are contacting for information. It does not necessarily mean that your browser isn’t working, or that you installed something improperly. Just like in the case of the TV and the TV station, sometimes problems are due to a bad TV, and other times they are caused by a problem at the TV station.

The server software for the World Wide Web is called an HTTP server (or informally a Web server). Examples are Apache and IIS. The client software for World Wide Web is called a Web browser. Examples are: Netscape, Internet Explorer, Safari, Firefox, and Mozilla. These examples are particular “brands” of software that have a similar function, just like Lotus 123 and Excel are both spreadsheet software packages.

There are many different information protocols/services besides HTTP (Hyper Text Transfer Protocol).

Some of these are:

E-mail (SMTP) - for sending electronic mail messages.

Usenet News (NNTP) - for having electronic group discussions.

File Transfer Protocol (FTP) - for transferring files between computers. Telnet - for running programs on remote computers. 
Various Others . . .

Each of these works in a client/server manner by having a “language” defined that allows the client and server to communicate with each other in order to give users the information they request. These different languages have different purposes, capabilities, and advantages.

One of the nicest things about the World Wide Web is that it provides “one-stop shopping” for getting information over the Internet. In the past, you would have needed to learn how to use many different software applications in order to use all these services. Now you can use E-mail, News, FTP, Telnet, WAIS, Gopher, and HTTP services all through your favourite Web browser.

1.2 CONNECT TO THE INTERNET

The Internet can turn your computer into a powerful tool for research, communications, and sharing. If you have kids, the Internet is a great place for them to find homework help and chat with friends.

2 
 
  
  
Connecting to the Internet is easy, and your service provider will do most of the  
technical work for you.   
To connect to the Internet

1. Find an Internet service provider, and choose a connection type.

2. If necessary, transfer an existing ISP account.

3. Set up your home network.

4. Install a network adapter.

5. Connect your computer to the network.

Find an Internet service provider

The first step in connecting to the Internet is to find an Internet service provider (ISP). The most important services an ISP offers are:

Internet access: Access any Web site, send instant messages to your friends, play online games, or use any other Internet service.

E-mail: You can access your e-mail with Microsoft Outlook Express or your Web browser. Most ISPs offer multiple e-mail addresses, so everyone in your family can have an account. ISPs typically provide spam filtering that reduces, but does not eliminate, unwanted messages.

Depending on your location, you might have several different choices for Internet access. Starting with the most attractive technologies for home Internet access, common Internet connection types are:

Cable modems. The best performing and most affordable option available to customers, most cable TV providers offer broadband Internet access.

DSL. An excellent choice for businesses, DSL typically offers better reliability than cable modems. However, DSL tends to be more expensive than cable modems for similar levels of service.

Dial-up. The slowest method of connecting to the Internet, dial-up enables you to connect to the Internet using your existing phone lines. Dial-up is convenient because it is available to any location with a phone. However, slow performance makes using the Internet frustrating.

Satellite: Satellite broadband services provide high-speed Internet access to any location with a clear view of the sky (currently available in North America and certain other locations). Satellite services may be the only broadband option for people living in rural areas. The cost of satellite services is significantly higher than other services. While you can transfer large files quickly with satellite, browsing the Web or playing online games can seem slower than with dial-up because of the delay caused by sending signals to and from satellites.

Additionally, ISPs are beginning to offer wireless or fiber broadband Internet access 
 in limited areas. 
 To find an ISP, you should contact your cable television provider for cable modem 
 service or your telephone company for DSL. Almost all cable and telephone companies 
 offer broadband Internet access, and they typically offer a discount if you purchase multiple 
 services from them. 
 Bandwidth 
 Internet bandwidth (the speed at which your computer can send and receive information) 
 is measured in either Kbps (kilobits per second) or Mbps (megabits per second). If you 
 are lucky enough to have multiple broadband options in your area, compare these factors: 
 Downstream bandwidth: This is the speed with which your computer can receive 
 information from the Internet. The higher the downstream bandwidth, the faster your 
 computer can display Web pages, transfer music, and download files. For most people, 
 downstream bandwidth is more important than upstream bandwidth, so the speeds tend to 
 be much higher. For example, a cable modem service might offer 6,000 Kbps downstream 
 and only 768 Kbps upstream. 
 Upstream bandwidth: This is the amount of data your computer can send to the Internet. 
 This isn’t important if you just plan to read e-mail and surf the Web, because your computer 
 only needs to send a small request in order to receive a large Web page or e-mail. However, 
 if you’re into online gaming or you want to send large files to people, then higher upstream 
 bandwidth is important, and you should choose the highest upstream bandwidth available. 
 Reliability and customer service: ISP reliability has increased significantly in recent 
 years; however, it is still not as reliable as your phone or television service. There is no 
 objective way to measure reliability and customer service, so you should talk to your 
 neighbors about their experiences and search the Web for reviews of ISPs in your area. 
 Transfer an existing account 
 No matter which ISP you use, you’ll connect to the same Internet. You’ll be able to 
 reach the same Web sites and send instant messages to all of your friends. However, if you 
 use the e-mail account provided by your current ISP, you will lose that when you switch 
 ISPs. 
 If possible, activate your new ISP account a week before you close your old ISP 
 account. Notify everyone you want to exchange e-mail with that you have a new e-mail 
 address, and ask them to update your address in their contact list. Then, if anyone sends an 
 e-mail to your old account before you close it, reply from your new address.

Tip: Your new ISP will provide you with an e-mail address. However, you do not
have to use it. Consider using a free Hotmail account instead. If you use Hotmail, you can  keep the same e-mail address no matter which ISP you use.

If you’ve registered your e-mail account with Web sites that you want to receive e-mail from, you’ll need to let those Web sites know that your address has changed. Examples might include online stores, forums, communities, financial services, and Microsoft Passport. It’s important to change your account while your old e-mail address is still available, because Web sites often send a confirmation e-mail to your existing address before allowing you to make a change.

Set up your home network

Your ISP brings the Internet to your home, but it’s your home network that connects your computer to the Internet. If you have a single desktop computer and it’s in the same room as your Internet connection, your home network will simply consist of a single cable (provided by your ISP) that runs from your modem or router to your computer. Your ISP will either set it up for you or provide you with instructions for connecting your computer.

If you have more than one computer, a portable computer, or devices such as an Xbox 360 or Media Centre Extender that you want to connect to the network, you can connect all the devices to the Internet simultaneously. For stationary devices, such as desktop computers and Xbox 360, you can connect them to a wired network. For mobile devices, such as a portable computer, you will need to install a wireless network. To help determine which type of network to choose, read choosing the type of network to install.

1.3 CONNECT YOUR COMPUTER TO THE NETWORK

Once your network is set up, you need to connect your computers and other network devices. For computers, first verify that they have a compatible network adapter, and install one if necessary. Then follow these instructions for the devices you want to connect:

To connect to the Internet, follow these steps (which may vary slightly, depending on the software required for your network adapter)

1. Shut down your computer and install your network adapter.Note: If you are installing a USB (Universal Serial Bus), CardBus, or CF card network adapter, you do not need to shut down your computer before installing the network adapter.

2. Start Windows, and log on as an administrator.

3. The Found New Hardware Wizard will appear. Click Yes, now and every time I connect a device. Then click Next..

4. The Found New Hardware Wizard asks you how you would like to find your driver. The driver is software Windows needs to communicate with your network adapter. Typically, it is included on the CD-ROM that came with your network adapter. Insert the floppy disk or CD-ROM, and then click Next.

5. If prompted, click Continue anyway. Software that does not have a digital signature has not been officially tested by Microsoft. However, it’s usually okay.

6. Windows XP copies the needed files and installs the software for your network adapter. On the final page, click Finish.

7. If prompted, click Yes to restart your computer. After yo

Title:
Web programming lecture notes

Subject:
Web Programming

Institute:
P.R.Engineering college

Web programming lecture notes

Web programming lecture notes in Web Programming uploaded at P.R.Engineering college

Summary / document preview text:

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