(1) A separately testable element specified in the design of a computer software component.~(2) A logically separable part of a computer program.~(3) A software component that is not subdivided into other components.~(4) See: test unit. Note: The terms "module," "component," and "unit" are often used interchangeably or defined to be sub-elements of one another in different ways depending upon the context. The relationship of these terms is not yet standardized.