When and why do you use Parallel Compression?

[peruviantorch]

I want to know experience and use cases for using parallel compression from other fellow producers.

In my case, when I’m producing a track I would use it a lot on Drums. Sometimes on synths.

[precords1275]

I use it a lot on vocals to bring up the perceived volume and retain some of the dynamics. I also use it on different stems that I really want to "glue" together like if I have all my toms to a sub group or I want to squeeze the bass and kick together.