What Is an API?
An API is a defined way for one program to ask another for something. Once you can read one request, you can read most of them.
Beginner7 min readDaksh BathlaDEFINITIONDevelopment
API
Application Programming Interface
A published set of requests one program will accept from another, and the responses it gives back. It defines what you can ask for without exposing how it's done.
EXAMPLE
A payment provider's API lets your code send an amount and a card token, and receive back whether the charge succeeded. You never see their systems.
WHY IT MATTERS
Almost every product is assembled from other people's APIs — payments, email, maps, models. Reading one is a basic literacy for building anything.