Okay kiddo, so there was a girl named Begum who went to a school called Denbigh High School. She wanted to wear something she called a jilbab, which is like a long robe, as part of her school uniform because it was important to her religion.
But the headteacher and the people in charge of the school, called the governors, said she couldn't because it wasn't part of the school's dress code. Begum and her family went to court and asked a judge to decide if she had the right to wear the jilbab at school.
The judge, who was like a grown-up who knows a lot about the law, listened to both sides and decided that Begum did have the right to wear the jilbab because it was important to her religious beliefs. The judge said that the school's dress code shouldn't stop her from practicing her religion.
So, the court said that the school had to let Begum wear the jilbab if she wanted to. This decision was important because it showed that people have the right to practice their religion even if it's different from what other people believe or what the rules say.