The first recorded description of the social interactions that could be enabled through networking was a series of memos written by J.C.R. Licklider of MIT in August 1962 discussing his "Galactic Network" concept. He envisioned a globally interconnected set of computers through which everyone could quickly access data and programs from any site.
In late 1966 MIT researcher Lawrence G. Roberts went to DARPA (Defense Advanced Research Projects Agency) to develop the computer network concept and quickly put together his plan for the "ARPANET" , publishing it in 1967.
HTML is one of many markup languages that have appeared in recent years.
In brief, a markup language provides guidelines for adding markup—in the form of special symbols—to text documents. These symbols describe the parts of the document.
Markup is needed because computers are quite stupid when it comes to understanding text. A computer can’t really tell whether a certain portion of a text is an abstract, a title, a heading, or a paragraph. Without some kind of additional coding, the computer doesn’t know how to display the text so that it looks like an actual document.
Word processing programs provide the necessary coding by means of proprietary formatting codes, but these have a gigantic downside: They work only if you’re looking at the document using the same word processing program and type of computer that created it. If you ever tried to exchange a WordPerfect file with a Macintosh MS Word user, you can understand the difficulties involved.
What’s hypertext? In brief, hypertext is a way of organizing information so readers can choose their own path through the material. Instead of clicking through sequentially organized pages, a hypertext user clicks specially highlighted text, called a hyperlink (or just a link for short), to go directly to information of interest.
When you mark up a document with HTML, you can define some of the text as a link, within which you embed the computer address of another resource on the Internet. This could be a document, a movie, a sound, an animation, or a file to download.
The whole purpose of a markup language lies in separating structure from presentation and, in so doing, enabling content developers to create documents that can be displayed faultlessly on any type of computer.
But this distinction hasn’t fared well. By the time HTML got to Version 3.2, it had been seriously eroded. The reason lies in the Web’s rapid commercialization. Actually, HTML was initially designed to enable physics researchers to make their preliminary papers available to other physics researchers.
Realizing that something drastic had to be done to rescue HTML, the World Wide Web Consortium (W3C)—the nonprofit, standards-setting body responsible for HTML—has published a specification for a new version of HTML, Version 4.01.
Every organization has its own rule-making body. In the case of the Web, the rule-making body is the World Wide Web Consortium (W3C). The W3C is composed of representatives from over 400 member companies who want to have a say in the standards. The W3C tries to balance the interests of the academy, the companies producing the Web browsers (notably Netscape and Microsoft), and the technology.
In the case of valign (an attribute frequently used to tell the browser where on the page you want an image or a table to appear, relative to text), your choices are top, middle, bottom, and baseline.
Please take a number (when you define a table, you may want the first column to be 25 percent of the screen width, the second column to be 50 percent of the screen width, and the third column to be 25 percent of the screen width.)
Begin your comment with <!--. Any text you put after the two dashes is comment. The browser will not even try to read it. Even if you use special characters, such as ampersands and slashes and quotation marks and angle brackets, your browser ignores everything it comes across until it sees -->.
Although keywords and page descriptions are optional, search engines commonly use them to collect information about your Web site.
Be sure to include detailed and concise information in your <meta /> tag if you want your Web site discovered by search engine robots.
Automatically redirecting users to another page
You can use metadata in your header to send messages to Web browsers about how they should display or otherwise handle your Web page. Web builders commonly use the <Meta /> element this way to automatically redirect page visitors from one page to another.
For example, if you’ve ever come across a page that says this page has moved. Please wait 10 seconds to be automatically sent to the new location. (Or something similar), you’ve seen this trick at work.
To use the <meta /> element to send messages to the browser, here are the general steps you need to follow:
1. Use the http-equiv attribute in place of the name attribute.
2. Choose from a predefined list of values that represents instructions for the browser.
These values are based on instructions that you can also send to a browser in the HTTP header, but changing an HTTP header for a document is harder than embedding the instructions into the Web page itself.
width: Specifies line width either in pixels or by percentage of display area width (which we call “the page” in discussion that follows) . For example, a rule can be 50 pixels wide or take 75 percent of the page.
size: Specifies the height of the line in pixels. The default is 1 pixel.
align: Specifies the horizontal alignment of the rule as either left (the default), center, or right. If you don’t define a width for your rule, it takes the entire width of the page. The alignment won’t make any difference.
noshade: Specifies a solid line with no shading. By default, most browsers display hard rules with a shade.
Paragraphs are used more often in Web pages than any other kind of text block. HTML browsers don’t recognize the hard returns that you enter when you create your page inside an editor. You must use a <p> element to tell the browser to separate the contained block of text as a paragraph.