WEBM is video the way browsers like it: open, royalty-free and built to stream. It was born in 2010, Google, out of its VP8 acquisition, and its real weak spot is life outside the browser: editors, TVs and Apple devices get picky.
MOV is Apple's homebody: gorgeous on a Mac, awkward everywhere else. The QuickTime container; often H.264 or HEVC, sometimes heavyweight editing codecs like ProRes. That makes it the right destination when what you need is shooting and editing on Apple hardware, where it's the native tongue.