Many search-engine robots (programs that automatically browse the Web gathering information for search engines to index) read the contents of the Description META tag. Some use the information to index your pages in their databases, and some also display the information below the link to your page in the search results instead of the first few lines of your document. Some search engines put a limit on the number of characters they will index, so it's a good idea to limit your description to the fewest number of words possible (for example, "Pork barbecue catering in the Albany, Georgia area" or "Unique Web design at a reasonable price for clients around the world").
Enter descriptive text in the field labeled Description.