Encapsulation is a very important factor when thinking about maintenance in a system. Having a classical OOP background, I've learned that encapsulation means bundling logic and data together into an isolated container. This way, we can operate on the container from the outside and treat it like a closed system.
There are many positive aspects of this approach when it comes to maintainability and accessibility. Dealing with closed systems is important for the organization of our code. However, this is even more important because we can organize ourselves while working with code: