Age of consent is the age at which a person is legally allowed to agree to something, such as having sex. Some countries, like the United States, have different age of consents depending on the states. Generally speaking, the age of consent is usually around 17-18 years old. This means that below that age, a person cannot legally say yes to any type of activity with another person, even if they want to. This is to protect young people from being taken advantage of.