introduction
A web client is a thing that requests information from a web server. It is like a library member asking a librarian for books but without the late return fines.
One of the services that runs on the Internet is the WWW (World Wide Web), commonly called the web. A series of protocols such as HTTP and HTML define how the WWW works. These protocols are maintained by W3C (World Wide Web Consortium). Many millions of web sites are distributed across the Internet. Each web site is supplied by a web server and consumed using a web client. A web client is a program that can fetch resources from web sites. A web browser contains a web client.
what it is
A web client is a consumer of the resources available at web sites. It fetches resources by starting a conversation with a web server. This conversation is routed across the Internet using TCP/IP protocols. The web client does not have to understand how this happens to start a conversation. It does need to be able to talk HTTP to the web server.
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In the beginning the first ever web client was a web browser. Web browsers every since have web clients built into them. Web browsers such as Netscape Navigator and Internet Explorer are both graphical web browsers which only run in a windowing environment. They can display pages in a variety of fonts and colors. Lynx is a text-based web browser that only needs a character terminal. Some companies write their own web browsers when they want more control over the user interface (the keyboard, video and mouse) and the processing that happens on the client computer.
Web browsers are not just web clients. Popular web browsers also include clients for other Internet services such as FTP and LDAP.
The basic job of a web browser is to display an HTML page and handle hyperlinks. Since web browsers have been used for so many years by so many people, there is a long history of bolting on extra bits of programs to make the browser do more interesting things. These extra programs are called plug-ins. Once it has these resources it must be able to do something appropriate with them. If the resource is music, the web browser plays it. If the resource is a java program, the web browser runs it. If the resource is a page, the web browser displays it. Web browsers also maintain lists of other programs and what they can deal with. When the web browser receives a resource that it cannot deal with, the browser looks through this list for a program that can.
Not all web clients are web browsers. Transactions between businesses using the WWW are automated. They send information to each other wrapped up in XML code. They don't need things like HTML rendering engines, plug-in programs or clients for other Internet services. A web client can be a specialised program written to provide a limited type of access to resources. A lot of programming languages supply building blocks for making web clients. This means a programmer only has to spend a couple of hours to write one. Specialised web client are often written in the Java programming language because Java is widely used on the Internet.
Security is essential to e-commerce. A web client can follow the SSL protocol to make sure its conversation with a web server cannot be understood by anything else on the Internet.
what it isn't
A web client is not necessarily a web browser, although all web browsers contain web clients. Some MP3 player programs can fetch tracks from websites. They have a built-in web client to do the work. This web client is not a web browser.
Web clients are not the customers of web design companies.
where it is
Web clients can be found in many devices that can connect to the Internet, from PCs to PDAs. There are very few in the LIC because the LIC provides a lot more resources than it consumes.
history
The first web clients were web browsers. Tim Berners-Lee created the first web browser in 1990 along with the first web server and, indeed, the entire WWW concept. He published the HTTP description which allowed programmers around the world to write their own implementations of the protocol and their own web clients to go with it.
Yeah, yeah, I can't find any facts and it shows.
