📕 Any piece of information enabling to recognize a private person, alone or combined with other information (phone number, client number, card number, etc.): they can be about salaries, clients, furnishers, etc.
You can pseudonymize personal data: this means that they can't be attributed to a specific person without searching for additional information. They are still subject to GDPR but they are considered as better protected.
You can anonymize personal data: this means that they cannot lead to the identification of a specific person anymore. It must be irrevocable. In this specific case, data is not subject to GDPR anymore.