It's a Digital Audio Workstation (DAW) used for producing music. It's one of the most popular and some people swear by the workflow but personally other DAWs make more sense to me.
Bitwig Studio inspires me the most. It's made by former Ableton Live devs (another one of the most popular DAWs) and has a similar workflow with some QOL features. I love the approach to modularity and sound design. You can get a free trial or buy it in monthly installments via Splice.