According to my tutorial before, SVN is a version control system. It allows users to keep track of changes made to any type of electronic data, typically source code, web pages or design documents. this is the alternative of CVS (another version control system).

there is a builtin client packaged with the binary of SVN, but if you need another client which has many feature on Windows OS Family, you might interested to install Tortoise SVN

from the website,

TortoiseSVN is an easy to use SCM / source control software for Microsoft Windows and maybe the best Subversion client there is. It is implemented as a Windows shell extension, which makes it integrate seamlessly into the Windows explorer. Since it’s not an integration for a specific IDE you can use it with whatever development tools you like.

in my side, i use this tools partially, when i need the simplier and more user friendly step to manage my code under versioning. with tortoise i can create local repository (with fsfs storage or bdb storage) and importing initial project to its. but not only that, when u do initial import, u can choose not only to local repos, but u can choose the remote repos too.  after the initial import u can just do checkout the project and working with it (commit and update).

in a versioned folder / source, u can do many operation to  versioned source/folder with easy rigth click, coz tortoise integrated with explorer shell.

with just right click, u can resolv, revert, view log, browse repos folder, cleanup lock, or another advance operation like create branch, merging, or even create a patch.

all svn command i describe before, can be done with single click without write down long command.