Data subjects are the people that share their data. A data subject is a person whose personal information (data) is being collected, stored, or processed. A data subject is the individual the data is about.
They have rights over their data, such as knowing how it’s used, correcting it if it’s wrong, or asking for it to be deleted (depending on the law/regulation, like GDPR). When you shop online, you are the data subject for your order history, payment details, and shipping information.