Ok kiddo, so imagine a house is like a big cookie. When someone dies, all of their things including the cookie, I mean house, becomes their estate.
Now, this estate can be divided up among the people the person who died wanted it to go to. It's like cutting the cookie into pieces and giving each person a piece.
But before that can happen, there are some grown-up things that need to be taken care of. Like checking to make sure the person who died didn't owe any money or have any debts.
Once everything is all good, the people who the person who died wanted to receive the cookie, or in this case, the house, can have it. They can choose to keep it or sell it to someone else who wants a big cookie house.
And that's basically what happens when someone dies and their house becomes part of their estate. It's like a big cookie that needs to be divided up and taken care of.