DLL:
1)it has versioning
2)it is not self executable
3)it runs in application process memory
4)it has no entry point
5)it is reusable

Exe:
1)it is self executable
2)it has no versioning
3)it runs in own memory
4)it have main function(Entry point)
5)it is self executable

Note:DLL is Superset of Exe