Okay, imagine you have a bunch of toys, like blocks and cars and teddy bears. You want to put them away so they don't get mixed up, right? So you separate them into different groups, like all the blocks in one pile, all the cars in another pile, and all the teddy bears in a third pile. Each group is separated from the others, so they don't mix together.
This is kind of like what separated sets are in math. If you have a bunch of numbers, like 1, 2, 3, 4, and 5, you might want to separate them into different groups too. Maybe you put all the odd numbers in one group and all the even numbers in another group. Or maybe you put all the numbers that are less than or equal to 3 in one group and all the numbers greater than 3 in another group.
When you separate sets like this, it's important that there's no overlap between the groups. Just like how you wouldn't want to put a block in the pile with the cars, you don't want to put a number in the wrong group either. So, 1 would go in the group with the odd numbers, while 2 would go in the group with the even numbers. You can't put 2 in the odd numbers group, because it doesn't belong there.
That's basically what separated sets are: when you take a bunch of things and put them into different groups, making sure not to mix them up or put any in the wrong group.