API
A menu of requests your app can make to another service, and the shape of the replies it will get back.
Like a restaurant menu and waiter, an API lists what you can ask for and carries requests and replies between your app and another service.
Apps use APIs to sign in users, store data, send emails, and take payments. In this course, Supabase, Resend, Stripe, and others offer APIs your app calls.
It looks like web addresses you call and data in JSON, a plain text format that holds names and values, for example a user name and an email.