Active User

An active user is anyone who performed a defined qualifying action within a specific time window — the exact action and window are set by each product, not standardized industry-wide.

This is a term with real definitional risk: two companies reporting "10 million active users" might mean wildly different levels of engagement depending on whether "active" means opened the app once, or completed a core value-generating action multiple times. Public companies disclosing active user metrics have occasionally faced scrutiny for defining "active" loosely enough to inflate the headline number — always check the fine print definition before comparing active-user figures across companies.