"Am ha-aretz" is a Hebrew term that means "people of the land." It is used to describe people in ancient Jewish society who were not very educated and did not know much about the Jewish laws and customs.
Imagine you are a kid and you go to school. Some kids in your class are really good at math and can solve tricky problems easily. But there are also some kids who struggle with simple math problems and don't really understand the concepts. In ancient Jewish society, the people who were good at understanding Jewish laws and customs were like the math whizzes, and the "am ha-aretz" were like the kids who struggled with math.
Being part of the "am ha-aretz" was not necessarily a bad thing, but it did mean that you might not know all the rules and traditions that were important in Jewish society. For example, you might not know what foods were okay to eat or how to observe the Sabbath in the correct way.
Today, the term "am ha-aretz" is sometimes used to refer to people who are not knowledgeable about a particular subject or area. It's important to remember that everyone has different strengths and weaknesses, and it's okay if you don't know everything about a certain topic.