Stateful
In plain terms
Retaining information between operations or requests.
Going deeper
A stateful component remembers prior interactions, so its behavior depends on history. This enables continuity but complicates scaling and reliability.
Under the hood
Stateful services need sticky sessions or shared stores to scale; statelessness is often preferred for horizontal scaling.
Examples
User sessions, shopping carts, databases, stateful widgets, game state.
Think of it like...
Like a conversation partner who remembers everything you've said so far.