The basics of html

The History of the Web

• The web was initially conceived and created by Tim Berners-Lee, a computer specialist from the European Particle Physics Laboratory (CERN) in 1989.
• In his words, there was "a need for a collaborative knowledge-sharing tool" to support scientific work in an international context.
• He and his partner Robert Cailliau created a prototype web for CERN and released it to the Internet community for testing and comments.
  
  The web is not synonymous with the internet, though some people may think so. Actually, the web is one way to utilize the infrastructure of the internet. In other words, the web is a subset of the internet.
  
• Since then it has grown into the web we know today under the guidance of the World Wide Web Consortium (W3C) that is a volunteer organization based at the Massachusetts Institute of Technology (MIT) with the responsibility for developing and maintaining common standards.
• Perhaps the single most important technological development in the history of the web, besides the creation of the web itself, was the development of graphical browsers in the early 90s. Beginning with NCSA's Mosaic and its evolution into Netscape's Navigator and Microsoft's Internet Explorer, these programs allowed users to browse the resources on the web in an extremely user friendly environment. This made the web a "fun" place and marked the beginning of the true web revolution.

The Nuts and Bolts of the Web

• So 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.
  
  

• 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.
  
  "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.
  
• 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.
• 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 Basics of HTTP

• As Hethmon notes in " An Illustrated Guide to HTTP , "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.
• 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.
  
  The "wires" is possibly a twisted pair network hooked into a local telephone company POP or a cable or fiber optics network hooked up to a corporate WAN or LAN that is also linked up to the national telecommunications/information infrastructure through a local telephone company. Whatever the case, the specifics of the information infrastructure is beyond the scope of this tutorial, but should be mentioned.
  
• Typically, these requests will be in some language and some format tha the computer understands, but in English sound something like, "hello software package running on a big hunk of computer, please give me the file called "mydocument.txt" that is located in the directory "/usr/people/myname".
• The "server software" will then access the server hardware, find the requested file, send it back over the wires to the "client" who requested it, and then wait for another request from the same or another client.
• Usually, the "client" is actually a software program, like Netscape Navigator, that is being operated by a person who is the one who really wants to see the file. The client software however, deals with all the underlying client/server protocol stuff and then displays the document (that usually means interpreting HTML, but we'll get there in just a bit) to the human user.
• The whole process looks something like the figure below:
  
  

• 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).
• 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). 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.