Entity
In plain terms
A domain object with a distinct identity that persists over time.
Going deeper
An entity is defined by a unique identity rather than its attributes, so it remains the same even as its data changes. Identity, not values, distinguishes it.
Under the hood
Contrasts with value objects; entities have lifecycles and are tracked by ID across changes.
Examples
User, Order, Account, DDD aggregates, database records with IDs.
Think of it like...
Like a person, your details change over the years, but you're still the same individual.