module(In programming, a collection of routines and data structures that performs a particular task or implements a particular abstract data type. Modules usually consist of two parts: an interface, which lists the constants, data types, variables, and routines that can be accessed by other modules or routines, and an implementation, which is private (accessible only to the module) and which contains the source code that actually implements the routines in the module)
HTTP module(A component that can be registered as part of the ASP.NET request lifecycle and that can read or change the request or response as it is processed. HttpModules are often used to perform special tasks that need to monitor each request, such as security or site statistics)
Commerce Module(An extension to the ASP.NET HTTP module framework. Commerce Modules are responsible for initializing run-time services specific to .NET-based Commerce Server applications. Commerce Modules are derived from the Microsoft.CommerceServer.Runtime.CommerceModule base class. A Commerce Module is an HTTP module)
