open closed principle

The open closed principle is a way of designing software so that it is easy to change when needed. It means that when you need to make a change, you don't have to change the whole program. Instead, you can just add on to the existing program, like adding new pieces to a puzzle. For example, you can build your program so that if you need to add a new feature, you can just add it to the program without changing the parts that are already in the program. This makes it easier to make changes and means that the program can stay up-to-date with new technology.