Both mov and mp4 are "containers", which can contain different kinds of codec. Both are usually h264 - mp4 especially - but they don't have to be. mp4 files can

Both mov and mp4 are "containers", which can contain different kinds of codec. Both are usually h264 - mp4 especially - but they don't have to be. mp4 files can contain many different variants of mpeg-4, including hevc. mov files can contain virtually anything.