Comparative fault is like sharing a toy with a friend. You both want to play with it but one of you accidentally breaks it. Now, instead of blaming just one person, you both have to take a little bit of the blame for the broken toy.
In real life, this means that if someone gets hurt or something gets damaged, it's not always just one person's fault. Maybe the person who got hurt wasn't paying attention and walked into a busy road, but the driver of the car that hit them was also texting and not paying attention.
Comparative fault helps decide how much each person is responsible for what happened. If the person who got hurt was 70% at fault and the driver was 30% at fault, the person who got hurt might only get 70% of the money they ask for to pay for their injuries.
It's like when you have to share the blame for breaking a toy. You both have to take responsibility for what happened, and maybe one person will get a bigger piece of the blame or toy than the other.