Personal data is information that relates to a specific person or can be assigned to a person. This includes, among other things, name, signature, date of birth and address data. Photos that show a person are also personal data. The same applies to files that can be assigned to a person in the overall context. There are also special categories, including health data, religion or sexual orientation, which enjoy special protection due to their sensitivity.
The personal reference only applies to people, not to legal entities such as limited liability companies or associations. However, the data of the representatives of a legal entity, such as their name, are personal data and are therefore subject to the GDPR.