Digital Audio Workstation (DAW).
At some point you might want to record some of the music you have been playing. Of course you can hold your phone next to your guitar and record, and at times you don't need more than that. But what if you want to do a bit more, actually record a full song, or multiple layers of instruments. That's when DAW's come into play.
What are some of your favorites? What are the ones that in specific cases do a thing really good, but in other scenarios not so much.
I'm using StudioOne. It came free with an audio interface I bought years ago. The workflow suits my needs and I find it easy to use.
I've used Ardour (on Linux) and Ableton (on Mac) in the past. I like both of them as well, but StudioOne has been simple to use and there are a lot of excellent videos on YouTube with tips and tricks.