The body tag specifies the appearance of the text, links, and backround for an entire html document.

here's a sample:

<BODY bgcolor="#000000" style="font-size: 12pt; color: #FFFFFF; font-family: veranda;" link="#3399FF" vlink="#9900FF">

This page would have a black background, white 9pt Arial font, light blue links, and purple visited links.

If you create a page w/o a body code the background would automatically be white, the text black, and the links blue.