Definition
Personally identifiable information, or PII, refers to any data that can be used to identify a specific individual. This includes direct identifiers like names and social security numbers, as well as indirect identifiers such as IP addresses or biometric data when combined with other information. In practice, organizations collect and process PII for various legitimate business purposes, such as customer service or personalized marketing. Understanding PII is crucial for implementing appropriate security controls and complying with privacy regulations, as its misuse can lead to identity theft and significant legal penalties. For example, a customer's full name combined with their billing address constitutes PII. It is important to distinguish PII from general demographic data, which is anonymized and cannot identify an individual. This concept is fundamental to cybersecurity domains and appears on certifications like CompTIA Security+, CySA+, and CISSP.