Compressors are such a flexible and useful tool, it's really worth exploring the many useful functions they perform. Analog compressors, particularly pedals tend to to be limited in the specific scope of things they can do, but if you start with the FAS Studio, you have access to all the parameters.
One example: You can go either way with the attack: set fast to crush the attack transient, or slow to exaggerate it.
Another: Using a compressor as a limiter can actually increase the perceived sense of dynamic range. By attenuating only the peaks going over a set upper threshold, thus allowing for wider dynamic excursions in the middle of the range. Particularly useful with clean tones or acoustic guitar in balancing arpeggiated notes with aggressive strumming.
Release time can be set long for sustain or short for a snappy drop off. Morph your guitar tone toward the banjo for a giggle.
Use a compressor to finesse texture: smooth stuff out, or get more articulate, go fatter, thicker, etc. Explore the FAS models for their unique characteristics.
Compression before the amp will have the greatest effect on the character of the guitar, Compression after the amp is generally used as a refinement.
I have a compression block set up (before the amp) with each of the four (ABCD) banks set up to address a particular circumstance: A Transparent peak limiting, B Subtle optical smoothing, C Sustaining, D 1176ish crunchify. Most of the time I don't use any compression, but as the block is just napping patiently there in bypass , I can roust it at any time to see if maybe compression is of benefit (and if so, what kind). It's easy enough to mix an appropriate dollop in parallel: and quickly ascertain if compression is the way to go. Then it's straightforward to pursue the appropriate adjustments.
With proper training: a compressor is not a one trick pony.
No, parallel compression is not the same thing as low ratio compression. This video contains visuals that can help you to understand the difference
Indeed: the Fab Filter videos are excellent instruction on what is going on with the various processes.