👉 A prerevision in computer science refers to a variable that is set to the value of another variable before it has been used. This can be useful for situations where one needs to store values until they are needed later, or when you want to make sure your code works correctly even if some variables have changed. For example, let's say you're writing a function that takes in two parameters: `x` and `y`. You might need to store the value of `y` until it is
