

I have worked with some excellent testers but I have also worked with a team that literally required us to write down the tests for them.
To be fair, that wasn’t their fault because they weren’t testers. They were finance people that had been seconded to testing because we didn’t have a real test team.
The current team is somewhere in between.
I think that the main difference is that developers tend to test for success (i.e. does it work as defined) and that testers should also test that it doesn’t fail when a user gets hold of it.