Just to add, the limit screws adjust how far inward and outward the derailleur sits in the largest and smallest cogs, the cable tension (via the barrel adjuster) tunes how the derailleur moves between those limits.
If you start adjusting the limit screws make sure the one for the largest cog (easiest gear) is properly set once you put your rear wheel back on. If it travels too far inward you can easily put your chain up and over the top. I’ve seen far too many destroyed rear derailleurs/derailleur hangers, ruined wheels and even cracked frames because this wasn’t adjusted properly.