I’m a new into Java programming

What is the difference between nextLine and readLine in Scanner class? I know that readLine is buffered, does that mean it’s mutable? and if it is mutable what does mutable mean, I thought that when we use nextLine, after we type something in the command prompt, it gets recorded, and deleting doesn’t work but that wasn’t the case, I found both literally the same, not being able to find a difference between both is making me go insane.

I tried different types of programs, alternating both readLine and nextLine, but I can’t seem to find any change.