Dynamic library

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For other uses, see Dynamic library (disambiguation).

In computer science, a Dynamic Library, also referred to as a Dynamically-Linked Library, is a computer library that implements the concept of dynamic linking. This term is often shortened to DLL.

In Microsoft Windows, linking to dynamic libraries is usually handled by linking to an import library when building or linking to create an executable file. The created executable then contains an import address table (IAT) to which all dll function calls are referenced to (each referenced dll function contains its own entry in the IAT). At run-time, the IAT is filled with appropriate addresses that point directly to a function in the separately-loaded dll.

Like static libraries, import libraries for dll's are noted by the .lib file extension. For example, kernel32.dll, the primary dynamic library for Windows' base functions such as file creation and memory management, is linked to via kernel32.lib.

As functions in static libraries can reference other static library functions, dynamic libraries can reference functions in other dynamic libraries.