GET and HEAD are not really "potent" as they don't cause state to change on the server (or at least shouldn't). So I usually prefer saying GET and HEAD are "safe".
The difference between safe and idempotent is:
- using an idempotent verb 0 or 1 times will have a different end state on the server.
- using a safe verb 0 or 1 times will have the same end state on the server.
GET and HEAD are not really "potent" as they don't cause state to change on the server (or at least shouldn't). So I usually prefer saying GET and HEAD are "safe".
The difference between safe and idempotent is:
- using an idempotent verb 0 or 1 times will have a different end state on the server.
- using a safe verb 0 or 1 times will have the same end state on the server.