What is the difference between screw and bolt?

I see two good answers before mine, and I would add that a screw is provided with a head to receive a screwdriver of some sort, while a bolt normally has a hexagonal head to be driven by a spanner or socket.

Screw is singular component which fastens by itself, even if it is driven with a screw driver or a spanner, it does the work of fastening something all by itself, whereas a bolt is a male component of a pair called (nut and bolt), which when used together does the work of fastening, or in case of machinery drive a slide, except when we have a tapped hole or internal threaded part on any one of the work which has to be fastened to the other with a bolt,in such cases also it may be considered as a screw.

A screw has a point of some sort, in which it can drive itself into whatever you are working with. A bolt, on the other hand, does not have a tip or point. With a bolt, there must be an existing hole, in which the bolt is inserted. Also, a "nut" is generally used to hold a bolt in place. Screws and bolts are different, just as screws and nails are different. They both have their place and use, and they aren't interchangeable. Hope that helps...

While both are fasteners, a screw has the capability of boring its hole and always has threads. While a bolt, on the other hand, may or may not have threads and typically must have its hole bored (by a tool) prior to insertion.

A screw has a point of some sort, in which it can drive itself into whatever you are working with. A bolt, on the other hand, does not have a tip or point. With a bolt, there must be an existing hole, in which the bolt is inserted. Also, a "nut" is generally used to hold a bolt in place. Screws and bolts are different, just as screws and nails are different. They both have their place and use, and they aren't interchangeable. Hope that helps...

Screw is singular component which fastens by itself, even if it is driven with a screw driver or a spanner, it does the work of fastening something all by itself, whereas a bolt is a male component of a pair called (nut and bolt), which when used together does the work of fastening, or in case of machinery drive a slide, except when we have a tapped hole or internal threaded part on any one of the work which has to be fastened to the other with a bolt,in such cases also it may be considered as a screw.

While both are fasteners, a screw has the capability of boring its hole and always has threads. While a bolt, on the other hand, may or may not have threads and typically must have its hole bored (by a tool) prior to insertion.