The DAW or Digital Audio Workstation is at the heart of every home studio. It is the software in which you will spend most of your time when recording and mixing. I think of a DAW as a recording studio in software, allowing you to perform multi-track recording and mixing much the same as you would in a professional recording studio
Reaper is my recommendation for a DAW for a home studio. It is very cheap costing only $60, but don’t let that fool you into thinking it compromises on quality. Reaper’s features and performance are comparable with other commercial DAWs costing many hundreds of dollars. I have been running Reaper as the centerpiece of my home studio for years – I made my 2 EPs in 2020 entirely in Reaper (check my About page for links to listen).