Running code without managing servers yourself - the cloud provider handles all the server management. Like ordering takeout instead of cooking at home.
AWS Lambda runs your code only when needed and you only pay for the time it actually runs, without managing any servers.
All are event-driven Function-as-a-Service (FaaS) offerings: you deploy code as functions, they auto-scale on demand, and you pay primarily for execution time and requests. Differences are mainly in triggers/integrations, runtime options, scaling limits, and observability tooling.