Personally Identifiable Information (PII) is any piece of data that, on its own or combined with other data, can identify a specific natural person. Common direct identifiers are names, email addresses, phone numbers, government IDs, and full IP addresses; common indirect identifiers are device fingerprints, browser cookies, and sufficiently fine-grained location data. Major data-protection laws — GDPR in the EU, CCPA / CPRA in California, LGPD in Brazil — define overlapping but not identical scopes of "personal data" or "personal information"; GDPR's definition is the broadest of the three.

In a self-hosting context

When self-hosting an OSS analytics or CRM tool, PII handling is mostly a function of which fields you choose to store. Plausible Analytics and Matomo both ship cookie-less, IP-anonymized modes specifically for GDPR-without-banner workflows; replacing Google Analytics with one of these is the usual minimal-PII pivot. For a CRM or helpdesk replacement, see High availability (your data, your backup story) and GDPR data residency (where it physically sits).