Have you ever heard of the book "Matilda" by Roald Dahl? It's about a really smart girl named Matilda who loves to read books, but people don't believe she's smart because she's young and a girl.
This is what the Matilda effect is all about - when people, specifically women, aren't given credit for their achievements or ideas because of their gender.
For example, let's say a girl comes up with a great idea for a new invention. But when she tells others about the idea, they don't take her seriously because they don't think girls can come up with good ideas about science or technology.
Or, maybe a woman is a scientist and discovers something really important. But when she shares her findings, people don't give her credit or recognition because they assume a woman couldn't have made such a big discovery.
This is not fair, and it's important for everyone to recognize the accomplishments of women and give them the credit they deserve regardless of their gender.