Personally Identifiable Information (PII)
PII is any information which can be used to identify, directly or indirectly, an individual human being.
It is often defined by obvious examples such as names, identification numbers, bank details and online identifiers. However, it also consists of references to the physical, physiological, genetic, mental, economic or cultural identity of an individual human being. For example, knowing the country of origin, the age or weight, and the neighborhood where a person lives could be sufficient, in some circumstances, to identify who that person actually is.
PII is a core concept of the well-known European General Data Protection Regulation (GDPR) and other regulations, such as the Swiss Federal Act on Data Protection. It now has paramount importance when dealing with data all over the world, as it requires special care and strong protection.