API Fundamentals Course
API Fundamentals
/
Intermediate

Types of APIs

Definition

Categorizing APIs based on their access permissions (Public, Private, Partner) and their architectural styles (REST, GraphQL, SOAP, gRPC).

Explain Like I'm New

Not all APIs are meant for everyone. A 'Private' API is only used by your own company's apps. A 'Public' API is open for anyone in the world to use (like the Pokemon API). A 'Partner' API is only for specific companies you sign contracts with.

Real World Example

Twitter has a Private API (used by the official Twitter iPhone app), a Partner API (used by Apple to integrate tweets into iOS), and a Public API (used by random college students building sentiment analysis bots).

Common Use Cases

  • •System Architecture
  • •Security scoping

Interactive Example

// 1. Web API (Over the Internet via HTTP)
fetch('https://api.github.com/users/octocat');

// 2. Browser API (Built into Google Chrome)
navigator.geolocation.getCurrentPosition((pos) => console.log(pos));

// 3. Library API (Using a third-party code library locally)
// The 'format' function IS the API of the date-fns library!
import { format } from 'date-fns';
format(new Date(), 'yyyy-MM-dd');

Interview Questions

basic

  • What is a Public API (also known as an Open API)?

intermediate

  • What is the difference between a Web API and a Library/OS API?

Flash Cards

Question

Public API?

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Answer

An API that is publicly available for external software developers to access, usually with minimal restrictions (though they often require an API key to track usage).

Question

Web vs OS API?

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Answer

A Web API works over the internet using HTTP (like fetching weather data from a remote server). An OS API works locally on a device (like your Javascript code asking the iPhone's iOS API for permission to use the local camera).