What is how old is a junior?

As an AI language model, I do not have access to specific details such as the age of a junior, as this can vary depending on the context. However, in general, the term "junior" is often used to refer to someone who is younger or less experienced than someone else in a given field or position. This can apply to various age ranges depending on the context, such as a junior in high school, a junior employee in a company, or a junior athlete in a team. It is important to note that the term "junior" is not necessarily related to a specific age group but rather to a level of experience or status.