FSFS or BDB

Both formats are equally official. BDB has problems if it is created on a NFS partition. FSFS has better performance, when directories with a great number of files in them are uploaded, but checking out is slightly slower for FSFS. However, from users' perspective and even from administrators' perspective to some extent, the type of the backend does not matter. The current document uses FSFS for the repositories. The differences between FSFS and BDB are explained at
http://svnbook.red-bean.com/nightly/en/svn.reposadmin.html.

Now when the repository is created, it can be configured to be accessed via several schemes: file://, svn:// or svn+ssh://, http:// or https://.

The scheme file:// can be used when the client is on the same machine as the server or the repository is mount on an NFS share. It is the most simple way and the least robust. We already saw it in action.

For the scheme svn:// the machine that hosts the repository runs the program svnserve that is a small server communicating with the clients via TCP/IP. The scheme svn+ssh:// means that the communication with the repository is done through an SSH channel.

The http:// or https:// schemes are maybe the most popular. In this case a client's requests to a Subversion repository are actually HTTP request handled by an Apache Httpd server that runs mod_dav_svn module.