[jQuery] Download JQuery

[jQuery] Download JQuery


Hello,
I want to download and start using JQuery.
Which one should I download?
And why the file sizes do no match?
For example, for
45.3Kb - http://code.google.com/p/jqueryjs/downloads/detail?name=jquery-1.2.1.min.js
14Kb - http://docs.jquery.com/Release:jQuery_1.2.1
Thanks,
Miguel