What does it mean to work a weeks trial?

Question

And do many employers do this?

Answer 1

I have done that before it was for a family owned conveniece store basically you work for like three weeks and they either pay you twenty dollars a day or not at all and they like you they keep if not you don't get the job its kind of like probationery period kinda of like try before they buy  

Answer 2

it means that the first week you work there they can let you go for any reason at all. in some cases it also means you are working for free.