Difference between .EXE and .DLL files

EXE

1. It is an executable file, which can be run independently.
2. EXE is an out-process component, which means that it runs in a separate process.
3. It cannot be reused in an application.
4. It has a main function.

DLL

1. It is Dynamic Link Library that is used as a part of EXE or other DLLs. It cannot be run independently.
2. It runs in the application process memory, so it is called as in-process component.
3. It can be reused in an application.
4. It does not have a main function.