Two products associated and produced from Apple are the MOV and the M4V. These are formats that are specifically file formats. The differences between the MOV and M4V formats are how they are used. iTunes uses the M4V format. There are other products that use the M4V format, including the iPhone, iPad, and the iPod.
The MOV, on the other hand, is used for QuickTime. Both are considered to be container formats. MOV is a little more powerful than the M4V, and that is because the MOV can be used for more codecs. These same codecs can’t be supported by the M4V. However, the M4V supports more portable devices than the MOV format. Both of these are important for file formatting.