A chondroitin sulfate proteoglycan is kind of like a Lego tower made up of little pieces.
The Lego pieces are made of something called chondroitin sulfate, which is like little balls stacked on top of each other.
Proteoglycan is like a special kind of glue that helps stick the chondroitin sulfate Lego pieces together.
When you put the Lego tower together, it becomes a big structure that helps support things. In our bodies, chondroitin sulfate proteoglycans help make up some of our tissues like cartilage and help keep our joints strong.