What is 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’. The GAC enables you to share assemblies across numerous applications.
The GAC is automatically installed with the .NET runtime. The GAC 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 GAC Tool (Gacutil.exe), that allows you to view and manipulate the contents of the GAC.