What is derusting?

Could you please explain to me what derusting is? I've heard the term mentioned in the context of cryptocurrencies and blockchain technology, but I'm not entirely sure what it entails. Is it a specific process, a technique, or a term used to describe a certain outcome? If it's a process, what steps are involved in derusting? And if it's related to cryptocurrencies or blockchain, how does it impact these fields? I'm eager to learn more about this topic and gain a better understanding of its significance in the world of finance and digital assets.