When I go on google and type in for example "used cars", google shows me the title and description of the site which it picks up from the meta tags. Exx Accent Used Cars Great used cars to choose from www.accentcars.com it will then send you to the home page I then type in new cars, again the same company shows but with a different description on Accent Used Cars But we also sell a great range of new cars www.accentcars.com This again send you to the same landing page So how does google pick up different descriptions from the same page based on what the search term was? I'm sorry if it's a really simple question, I've only been attempting to learn SEO for a few weeks.
Google call it a snippet - they generally use the title and description in the metatags, but may also use the description from dmoz, and alternatively may use text from the page - but what prompts one choice rather than another is another of those google mysteries. There's a video here from Matt Cutts about snippets http://www.mattcutts.com/blog/video-anatomy-of-a-search-snippet/
Cheers Magda, started watching the vid, you're a star. Hopefully it'll shed a little bit more light on the subject.