I'm working on a personal project and I've found myself switching between doing some refactoring for a day or two and then some feature-adding for a few days. I like it, and I noted it was similar to how an instructor I worked with wanted to rework the class website. First, she froze the features and worked on refactoring the website, then once that was done, she focused on the features and only noted the things to refactor.
What is this process of refactor-features-repeat called?
[Context: I am a PhD student in computer science in the USA. My experience with software engineering per se was a short software engineering internship, but it was not at a company whose main product was software.]