What is the best definition of personally identifiable information (PII)?

The best definition of personally identifiable information (PII) is data that is collected by businesses to distinguish identities of individuals. PII encompasses any information that can be used to identify, contact, or locate a person. This includes names, social security numbers, addresses, phone numbers, and other data that can be linked back to an individual. Understanding PII is critical in contexts such as data privacy, security regulations, and compliance with laws that protect personal information.

In contrast, a collection of random data does not constitute PII because it lacks specific identifiers linked to individuals. Information that cannot identify an individual means it does not meet the criteria for PII since it would not be tied back to a particular person. Lastly, general public demographic data, while it may contain information about age, gender, or general location, typically does not provide enough detail to identify specific individuals and therefore is not classified as PII.