What Is SVN And How Do I Use It?

[Sealy12103]

Apparently I need SVN For a Map I want To Play Called RP_Evocity2 But I need Something Called A SVN, here is the piece of text in the readme talking about the SVN's :

Current svn's for the map. (You need tortise SVN or another svn client for this read up on how to do it im not telling you everything.)
______________________________________________________________

SicknessModel

[url]http://subversion.assembla.com/svn/SicknessModel/[/url]

Evocity2

[url]http://subversion.assembla.com/svn/Evocity2/[/url]

Now You do not need Sicknessmodel but if you don't have evocity2 you will be missing textures and you will not hear all the sounds.

So i have no idea what he is talking about so can someone please tell me how to work SVN with the links.