It is a tool with a heavy part on a long handle, used for hitting nails into wood. However, the usage of this tool is quite various, i.e. not only for hitting nails into wood. We may use it to hit other things.
Nut is a small piece of metal with a hole through the middle which is screwed onto a bolt to fasten things together. Meanwhile, bolt is a screw with a flat head and no point, for fastening things together.
