Many search-engine robots (programs that automatically browse the Web gathering information for search engines to index) read the contents of the Keywords META tag and use the information to index your pages in their databases. Some search engines put a limit on the number of keywords or characters they will index, and some ignore all keywords if you go beyond the limit. For this reason it's a good idea to limit your keywords to a few well-chosen words.
Enter your keywords, separated by commas, in the field labeled Keywords.