In software development, "old" code is often "rewritten" because it might not be well understood (or be relevant) since features have changed (or evolved or removed) or simply because the developer did not have enough time to write code adhering to best practices.
Sorry for being thick, but what does refactor mean?
Refactor means to "rewrite".
In software development, "old" code is often "rewritten" because it might not be well understood (or be relevant) since features have changed (or evolved or removed) or simply because the developer did not have enough time to write code adhering to best practices.