GAC stands for Global Assembly Cache.

• Any computer where the CLR is installed has a global assembly cache.
• Global Assembly Cache stores ASSEMBLIES designated to be shared by multiple applications.
• It's a method to store DLLs in such a way that it can be ACCESSIBLE globally without worrying about any conflicts.
• Versioning is simple on the grounds that the GAC can hold numerous versions of the same DLLs without any issues.
• Bin folder of the application containing the local COPY of DLL isn't required, so a couple of megabytes can be saved on the HARD drive.
• Assembly can be installed in GAC by using a developer tool called the Global Assembly Cache tool (Gacutil.exe), provided in the Windows Software Development Kit (SDK).

Add, Remove and View Assemblies in the GAC

• To install an assembly in the GAC, use the command as below:

Note: full path must be mentioned so that the tool gets the correct assembly.

• To remove an assembly from the GAC, use the command as below:

Note: Only an assembly name is required. This command will remove all versions of the assembly.

• To remove a specific version of an assembly, additional versioning INFORMATION is required:

• To view the contents of the GAC:

gacutil / l