Yes. It's the official Apple Quicktime format .. Apple's equivalent to AVI. So that means it's a container file & the actual file format inside the container might be anything.

Generally (not always), .mov files you find on the gnutella network are Porn advertisments, short video excepts. And they appear to use some strange video format within the .mov container.

Some tips about videos here Movie download issues (click on blue link) (2nd last post has information on best video formats.)

Also these Music tips also apply to videos: How to find music