We all know about stacks. They're like a bunch of pancakes in a pile. The last one you put on is the first one you take off, and gravity makes it work. The stack is a notional data type representing a last-in-first-out (LIFO) structure. It's made up of homogeneous elements with no inherent order but can be ordered through "push" and "pop" operations on the topmost part. The push operation adds an element to the stack, while the pop operation removes a piece from the top position. Imagine a stack of pancakes. You can always see the top pancake, but you must know what's underneath it. That's how stacks work in computer science. You can add or move objects from the stack, but you only know what's at the bottom once you remove everything else. We call them "last in, first out" data structures. They work like stacks of plates at a buffet. When someone comes in and puts a plate on top of the dish is pushed back so that it is on top. When they leave, their plate gets taken away first because it was added last it's technically still on top even though it's buried under all the others. For example, imagine you're playing with friends trying to find keys for an imaginary door: when one friend finds theirs first, everyone else knows that hers must be close by! It is how stacks work when someone adds something new to the pile (like another key). It's time to get your stack hats on. There are two types of piles: dynamic and fixed-size. If you choose a dynamic stack, your stack size can change during execution, but your program will explode if it gets too big. If you select a fixed-size stack, you're stuck with what you've got, but if you try to add an element to an already full stack, your program will overflow its bounds and collapse into a black hole of despair. If that sounds like fun, then you should try it out.