Great visualization of Guitar Action - action, relief, backbow, etc

[Socio]

Also worth checking this post where Gibsons Master Luthier goes through everything in a series of videos.

Recently discovered 1967 Gibson documentary

@MAT1953 If you find yourself with some time to kill and without the guitar at hand you may enjoy this series of videos. I find their master luthier very interesting and knowledgeable.