Competence in law means that a person, usually a judge, has the ability and authority to make decisions about a certain case. Think of it like a teacher being in charge of their class - they have the power to make decisions about what the students are learning, how they behave, and what consequences they face.
Similarly, a judge has the power to make decisions about a legal case, to decide what is right and wrong, and to give orders to people involved in the case. They have to follow certain rules and laws to make sure they are fair and just.
However, just like a teacher can't teach a subject they don't know, a judge must have the right skills, knowledge, and experience to make these decisions. This is why judges usually have a lot of education and training in the law.
If someone is not qualified to make decisions about a certain case, they are not competent, and their decisions can be challenged in court. It's like if a student tells their teacher something that is wrong, the teacher will correct them. So, it's really important that judges know what they're doing so they can make good decisions that are fair to everyone involved.