The document discusses software refactoring, which is a process of restructuring existing object-oriented computer code, changing the internal structure of software without changing its external behavior. Refactoring improves nonfunctional attributes of the software without affecting its functionalities. It aims to improve factors such as code readability, extensibility, reuse and maintainability. Refactoring techniques include extracting methods, moving features between objects, inline changes and renaming packages and classes without changing the overall result of the software. Regular refactoring is important for long-term maintenance of software systems as it reduces technical debt that makes software harder to evolve over time.