Dynamic-link libraries serve much the same purpose that standard libraries do, but they also have the following advantages:

• Applications link more quickly. With dynamic linking, the executable code for a dynamic-link function is not copied into the .EXE file of the application. Instead, only an import definition is copied.

• Applications require less disk space. With dynamic linking, several different program applications can access the same dynamic-link function stored in one place. Without dynamic linking, the code for the function would be repeated in every .EXE file.

• Libraries and applications are independent. Dynamic-link libraries can be updated any number of times without relinking the applications that use them. If you are a user of third-party libraries, this is particularly convenient. You receive the updated .DLL file from the third-party developers, and you only need to copy the new library onto your disk. At run time, your applications automatically call the updated library functions.

• Code and data segments can be shared. Code and data segments loaded from a dynamic-link library can be shared. Without dynamic linking, such sharing is not possible because each file has its own copy of all the code and data it uses. By sharing segments with dynamic linking, you can use memory more efficiently.