Global Assembly Cache (GAC)
Each computer on which the Common Language Runtime is installed has a machine-wide code cache called the 'Global Assembly Cache'. GAC is a folder in Windows directory to store the .NET assemblies that are specifically designated to be shared by all applications executed on a system. Assemblies can be shared among multiple applications on the machine by registering them in global Assembly cache(GAC).
The GAC is automatically installed with the .NET runtime. The global assembly cache is located in 'Windows/WinNT' directory and inherits the directory's access control list that administrators have used to protect the folder.
The approach of having a specially controlled central repository addresses the shared library concept and helps to avoid pitfalls of other solutions that lead to drawbacks like DLL hell.
The Global Assembly Cache Tool (Gacutil.exe), that allows you to view and manipulate the contents of the Global Assembly Cache.
Where is GAC (Global Assembly Cache) located?
GAC is located in %windir%\assembly (for example, C:\WINDOWS\assembly) and it is a shared repository of libraries.
How to view the Contents of the Global Assembly Cache (GAC)?
At the Visual Studio command prompt, type the following command:
gacutil -l or gacutil /l