Overlay (programming)

When we talk about overlay in programming, we're talking about a way of making the most efficient use of the computer's memory. Think of memory like a big bookshelf in a library. The computer stores all of the programs and data it needs to run on this shelf, and it has to be organized in a specific way so that the computer can find everything it needs quickly and easily.

But sometimes, the programs we want to run are too big to fit on the shelf all at once. This is where overlay comes in! Overlay is like taking a big book and breaking it up into smaller chapters that we can read one at a time. When we need to use a certain chapter, we can take it off the shelf, read it, and then put it back when we're done so that we can take another chapter off the shelf.

In programming terms, overlays are like sections of a program that can be loaded into memory as needed. This allows the computer to use its limited memory resources more efficiently, because it doesn't have to keep all of the program's code and data in memory at the same time. Instead, it can just load the necessary parts of the program into memory when they're needed, and then swap them out for other parts as required.

So, in summary, an overlay in programming is a way of breaking up a large program into smaller sections that can be loaded into memory as needed, allowing the computer to use its memory more efficiently. Think of it like taking a big book and breaking it up into smaller chapters that we can read one at a time!