Learner's definition of MODULE
1 : one of a set of parts that can be connected or combined to build or complete something
factories that build engines, transmissions, brakes, and other modules for cars
(chiefly Brit) This is a modular course of three components, and students can take those three modules in any order.
2 : a part of a computer or computer program that does a particular job 3 : a part of a space vehicle that can work alone