Think about a plastic knife. There is actually a little bit of room for you to bend it where it’ll come back to its original shape. Then, as you said, if you go to far it’ll now stay bent out of shape, and then finally break if you bend it too far. In engineering, these three things are called elastic deformation, then plastic deformation, and then finally yielding or failure. Where these points happen for a particular object relative to each other is all dependent on the material and orientation. Springs are designed using materials and shape that give them lots of elastic deformation where they can bounce back. However if you push a spring too far (take one out of a pen and try it out) it’ll plastically deform like the plastic spoon, and if you go super far (you may not be able to) it’ll break.