Refactoring is a disciplined technique  for restructuring an existing body of code, altering its internal structure without changing its external behavior. The goal of this technique is to improve the readability, maintainability, scalability, and reusability of the code while reducing the cost of maintenance.

In other words, Refactoring is a continuous and iterative process over time that helps developers improve and keep their code up-to-date. This process involves small changes that individually help improve the code.

For example, if there is code that has become less readable and understandable, Refactoring can make a significant improvement in the code.