A credential is proof that someone has the training, knowledge, or authority to do something. A doctor's medical degree is a credential showing they studied medicine and can treat patients. A lifeguard's certification is a credential proving they know how to save swimmers in trouble. Your student ID is a credential that shows you belong to your school.

Credentials matter because they help us know who to trust with important responsibilities. You wouldn't want someone operating on you who just claimed to be a surgeon without any credentials to prove it. Similarly, colleges ask for your high school transcripts and test scores as credentials showing you're ready for college-level work.

When you present your credentials, you're giving others good reason to believe in your abilities. A teacher has credentials in education, a pilot has credentials to fly planes, and a chef might have credentials from culinary school.

Sometimes people use the word more broadly: “What are your credentials for giving advice about dogs?” someone might ask, wanting to know what experience or knowledge makes you qualified to speak on the subject.