Less and lesser

What's the difference between 'less' and 'lesser'? I guess, the latter just means 'less important' or 'minor'.

Please let me know if I'm right.

He is lesser/ less known artist.

I guess, here both can be possible depending on context. If the sense is that 'he is less known than someone', it's 'less'. But, if the sense is that 'he is not so greatly known', it's 'lesser'.

Please check if my assumption is correct and clarify the difference!