Because browsers are designed to display documents on any platform with any size and resolution screen, using whatever fonts are available on the local computer, the markup must be much more flexible than that used by a typical word processing program. This tells the browser to display all the text between these two tags as a very large heading, on a line of its own, with a blank line both above and below it. When creating web pages, it is very important to keep in mind that you are working with blocks contained within start and end tags that tell the browser how to display the block contents and that your ability to specify formatting details within the block is often very limited. This is the text that appears in the blue bar at the top of the Netscape Navigator window. Everything that the viewer sees in the web page will appear here, between the BODY start and end tags.
Elements can have various attributes that specify the properties of the block.
For example, within the BODY element you can specify the background color or image of the web page, plus the colors of the normal text, the link text, the visited link text, and the active link text. These attributes will be contained within the angle brackets of the element's start tag. See also this more detailed explanation of some basic HTML tags .