What is a subadvisory fee?

Could you please explain what a subadvisory fee is? Is it a separate charge from the regular advisory fee, or is it somehow related? How does it differ from other types of fees that investors may encounter when working with financial advisors? Are there any specific circumstances where a subadvisory fee might be applied, and how does it impact the overall cost of investing? Thank you for your time and clarity in answering this question.