Usually we don’t talk about data in general, but about personal data instead. Personal data is information that relates to you as an individual and allows for your identification. This data reveals facts about your personality and your private life, for example, your date of birth or your appearance.

There are special categories of personal data which are considered particularly sensitive. This data reveals an individual’s racial or ethnic origin, political opinions, religious or philosophical beliefs, sexual orientation, trade-union membership, and can relate to an individual’s health or sex life. Biometric data and genetic data also are special categories of personal data.

These categories of personal data are considered sensitive because of their particularly private and intimate nature.  Because of this, such data can be easily abused and used against someone, for example as a basis for prejudice or discrimination. Therefore, its processing is generally prohibited but with some exceptions stipulated by law. One of the exceptions is a person’s consent in a written form. You can read more about situations when processing of special categories of personal data is allowed as an exception in the General Data Protection Regulation.

Personal data can also be categorized according to the sphere to which it belongs. For example:

• medical data (data concerning health), such as a patient’s blood test results and cellular samples

• biometric data, which reveals an individual’s physical characteristics 
  For example, fingerprints or digital photos of someone’s face that have been obtained for the purpose of identification

• personal data relating to criminal convictions and offences

Data can exist in many different forms. It may be written on paper or in electronic form, contained in written or spoken communication between persons, it may also be expressed in an image, video or sound, or even enclosed in cellular samples and fingerprints.