Explanation of how API works? code example

Example 1: what is an api

An application program interface (API) is a set of routines, protocols, and
tools for building software applications.

Basically, an API specifies how software components should interact.
Additionally, APIs are used when programming graphical user interface (GUI)
components.

A good API makes it easier to develop a program by providing all the
building blocks. A programmer then puts the blocks together.

Example 2: what is an api

An application programming interface (API) is a computing interface which
defines interactions between multiple software intermediaries.

It defines the kinds of calls or requests that can be made, how to make them,
the data formats that should be used, the conventions to follow, etc.