The stated goal of the WebDAV (DAV) working group is (from the charter) to "define the HTTP extensions necessary to enable distributed web authoring tools to be broadly interoperable, while supporting user needs", and in this respect DAV is completing the original vision of the Web as a writeable, collaborative medium.

But, people working on DAV have had goals which extend beyond simple web page authoring. Some view DAV as a network filesystem suitable for the Internet, one that works on entire files at a time, with good performance in high-latency environments. Others view DAV as a protocol for manipulating the contents of a document management system via the Web. An important goal of DAV is to support virtual enterprises, being the primary protocol supporting a wide range of collaborative applications. Importantly, a major goal is the support of remote software development teams. A final goal of DAV is to leverage the success of HTTP in being a standard access layer for a wide range of storage repositories — HTTP gave them read access, while DAV gives them write access.

Well, the website clains WebDAV in 2 minutes .. I think 10-20 minutes is more realistic :-). A good starter.

Apache2 already comes with mod_dav.