What are the differences between the extensions EXE and DLL?

Both EXE and DLL are extensions of a file but both are different. The EXE extension is used to make any file executable and on the other hand, DLL extension is used with the files that can be loaded and executed by other programs dynamically. A single file with a DLL extension can be used by many different programs. The DLL files can help in reducing the space taken by individual files of the programs.