n. A set of pieces that work together in unison as a mechanism or device.n. A congregation of people in one place for a purposen. A legislative bodyn. assembly languagen. In Microsoft .NET, a building block of an application, similar to a DLL, but containing both executable code and information normally found in a DLL's type library. The type library information in an assembly, called a manifest, describes public functions, data, classes, and version information.