Watch movements

[mnl]

Hi!

I'm new here, just started reading lots of threads here a few days ago and I love seeing all your watches. You are all obviously super passionate about watches and while I've always loved watches, I'm kinda just getting started learning more about them besides just knowing I like how they look and being amazed by how automatic watches work.
Over the last couple of months I've been reading a ton trying to decide if I was making the right choice on my watch purchase, and I've noticed in lots of the reviews and comments when people are talking about a watch they say "it's an incredible movement" or something along those lines. Aside from some movements from the best brands like AP, Patek, etc, having an incredible finishing or something obvious like a tourbillon, what does this mean? For example, one of my favorite watches, the AP 15407, has a double balance wheel and on the website it is mentioned as an important feature of that watch. What does this mean for the movement?
Are there any videos or whatever that you would recommend to learn more about movements and what makes one movement more special than others?