What is the difference between fasteners, bolts and screws?
Fastener is a general term to describe something which is used as a restraint for holding things together or attaching to other things.
The main physical distinction between screws and bolts is that screws are entirely full of threads while bolts contain shanks without threads. However, a better interpretation of the differences between the two is that bolts are always fitted with nuts. On the contrary, screws are normally used with tapped holes.