The black market is an illegal market where people buy and sell things that are not allowed by law. It might include drugs, weapons, counterfeit goods, and things that are not taxed or regulated. The black market is dangerous because it can involve criminals and it is hard to find out who is selling what. This can make it hard to trust what you are buying and you might not know how the item was made or who you are buying it from, so it can be dangerous.