What is Refactoring?

Refactoring is the process of restructuring existing computer code—changing the factoring—without changing its external behavior. It is intended to improve the nonfunctional attributes of the software, such as readability, to reduce complexity; to improve maintainability; to improve performance; and to improve program structure to improve extensibility. Usually, it involves applying a series of small, behavior-preserving transformations, each of which 'cleans up' some aspect of the code. Common refactoring techniques include extracting methods, renaming variables and methods, and moving code to more appropriate classes or modules.