Okay, so imagine you have five days in a row where you have to do some work, like going to school or helping your parents with chores. This is called a workweek.
After those five workdays are over, you get two days off to do whatever you want. This is called a weekend.
Think of it like a carrot and a stick. The workweek is the stick that makes you do stuff, like a horse with a carrot hanging in front of it. Then, the weekend is the yummy carrot that you get as a reward for working hard during the workweek.
So, you work hard and learn a lot during the week, then you get to relax and have fun during the weekend. It's like having two different kinds of days for different things, just like how you have a different set of clothes for going to school and going to a party.