| exact match keyword | A domain name that contains your target keywords. |
| follow links | Links that have influence on the rankings of the linked site. These links help communicate a signal of trust in a web page to search engines. |
| caffeine | Googles web indexing system. Caffeine is the index, or collection of web content, whereas Googlebot is the crawler that goes out and finds the content. |
| comment system | the way that users can leave feedback on a blog. |
| extensible hypertext markup language | XHTML extends HTML to include XML formatting. |