MOV files are widely used and you may come across them in multimedia applications, video recordings. Since they were created for Apple Quick Tme Player, but the MP4 format is more popular on Windows platforms, it is better to convert them.

They can be decoded with programs that can be downloaded from the Web to perform conversions of different video formats directly on the computer, one of the best being Video to Video Converter.

but if you only need to decode a few MOV files it is advisable to use online decoders. 

Among many, this is the best decoder I've found that has no time or size limits, it's not very fast but it's free, reliable and works very well:

MOV to MP4 Converter – 100% Free 

Enjoy your conversions!