Imagine you are at a playground and there's a really cool slide that everyone wants to use. But only one person is hogging the slide and not letting anyone else use it. That's not fair, right?
Now, imagine that instead of a playground, we are talking about important things that people need to use all the time, like a hospital or a power plant. And instead of one person hogging the thing, it's a company that owns it and won't let other people use it.
That's where the essential facilities doctrine comes in. It says that if something is really important for people to use, then the company that owns it can't be greedy and keep everyone else from using it. They have to share.
This doctrine can be applied in lots of different situations, like if one telecom company owns all the phone lines in a town, they can't refuse to let another company use them, because then people wouldn't have a choice in which telecom company to use.
Overall, the essential facilities doctrine is a way to make sure that everyone has access to important things, even if someone else owns them.