Search Trends

The "Top keywords over time" graph shows you the performance of all your keywords simultaneously, so you can compare and see which are the most effective over time.

The "Top referring search engines" is very useful as it tells you which are the top referring search engines( thus, more detailed information distilled from Top referrers).

The "Top Keywords" table sums it all in one as it shows you the number of visitors that used each of the top keywords and to which page on your site this keyword has brough them.