Introduction to REST APIs for Absolute Beginners

Name: Introduction to REST APIs for Absolute Beginners
Rating: 4.6 (8294 reviews)

Learn how to use Postman to build REST & GraphQL requests

Created byValentin Despa, Valentin Despa - Support

Last updated 5/2026

English

What you'll learn

Create GET, POST, PUT, DELETE requests
Understand HTTP messages
Understand GET vs POST request method
Work with real-world APIs
Use Postman

Course content

5 sections • 51 lectures • 3h 24m total length

Brief history of APIs8:58
Trace the history of network APIs from 1950s interfaces to modern REST, SOAP, and GraphQL. Learn how clear interfaces enable interchangeable components and why REST dominates today.
Why do we need APIs? An example RPC call9:15
Welcome to the course - please watch!2:47
Valentine introduces the course, explains review timing, and guides students on video quality, resolution, captions, Q&A, and getting help through announcements and offline viewing.

Section overview1:06
Explore the essentials of http as the foundation for working with APIs. Practice understanding http messages with hands-on exercises in Postman.
HTTP message structure8:24
HTTP request method (GET, POST, PUT, DELETE, ...)7:52
Introduction to Postman (tool for working with APIs)4:07
What are query parameters? ...6:58
What are path parameters? ...9:57
Query parameters and path parameters
HTTP headers10:00
HTTP headers: Content-Type header4:12
HTTP headers: Authorization header4:57
HTTP headers: Cookie header (Cookies)3:18
HTTP body6:53
HTTP status code (200, 301, 401, 403, 404, ...)7:08
Conclusion0:22

Section overview1:15
Explore REST APIs, their design theory, and key terms like resources and endpoints, and learn to read Swagger or Postman documentation while practicing hands-on API concepts.
What is REST?2:42
Explore representational state transfer as an architectural style for building APIs, outlining its rules, non-standard nature, and how REST concepts describe representing objects and transferring them between client and server.
What is a resource?7:32
Hands-on API Car fleet management0:41
What is JSON?9:48
Learn JSON as a key-value data format and open standard for exchanging data between different systems, using strings, numbers, arrays, and nested objects, with language independence.
API Documentation5:11
Explore how api documentation communicates endpoints, resources, and http methods, with formats such as html, pdf, swagger, postman collections, and openapi, and distinguish public from private apis.
What is Swagger?3:53
Explore how Swagger, now Open API, describes REST APIs through a machine-readable specification and Swagger UI, detailing endpoints, models, and operations for car fleet management.
How to create a GET request - Part I4:53
Learn how to create a get request to fetch all cars from a car fleet management API, use try it out and Postman, and view JSON responses.
How to create a GET request - Part II4:24
Learn to construct a get request with a path parameter to fetch a single car, handle not found 404 cases, and test with Postman and Swagger.
Assignment - GET0:33
Assignment solution - GET5:36
Invalid JSON7:51
How to create a POST request3:32
Post a JSON car object to the /cars endpoint using Swagger and Postman, testing creation and observing the server return the new car with an ID.
Common errors3:55
Assignment POST0:50
Assignment solution - POST5:00
GET vs POST & What is a Cache4:58
How to create a PUT request4:03
Use the put method to update an existing car by sending the full data, including the ID, to the /cars endpoint; post may update in APIs, but put is preferred.
POST vs PUT1:36
Assignment DELETE0:20
Practice deleting unnecessary database entries using the proper HTTP delete method guided by the API documentation.
Assignment solution DELETE2:40
What is CRUD?1:10
Which HTTP verb to use3:10

Section overview0:20
What is Giphy?4:19
Register a Giphy account and create an app to access the API, learn via the quick start guide, and use Postman with an API key for requests.
How to search for GIFs using the API5:25
How to get a GIF through the API3:47
How to create a GIF (optional)1:17
Practice uploading data by converting a short video into a gif, using an online service, then save the gif locally; the exercise is optional and shareable in the Q&A.
How to upload a file using Postman2:22
Assignment0:18
Assignment solution1:02
Postman collection for Giphy0:12
Clean-up1:59

Requirements

The possibility of installing new tools on your computer.

Description

To work with APIs we will use the Postman app! Postman allows you to quickly create a request with the required HTTP method and parameters, set the body, headers, submit the request and easily inspect the results.

Postman can help if you are developing APIs as well! I have created this course for testing engineers and well for software developers. Postman can help you during the development of your API as well as after the API is completed, by running tests that make sure your API is still working as intended.

Postman has over 10 million users worldwide and continues to grow. This course will introduce you to Postman and is suited for beginners. You will learn how to build API requests with Postman, how to inspect responses debug any issues.

Postman has grown to be a complex tool that has many capabilities

So let’s look at what you are going to learn during the course:

Start with simple requests
Advance towards more complex scenarios
Upload files
Learn about REST
Work with real APIs
Learn to deal with authentication/authorization

So after this course, you will have an overview of Postman and can later decide in which areas you want to learn more.

Excited to learn about Postman? Sign up today!

Legal Disclaimer

This course is an independent educational resource and is not endorsed by, affiliated with, or associated with Postman, Inc., or any of its products. Postman is a trademark of Postman, Inc. All product names, logos, and brands mentioned in this course are the property of their respective owners.

This course contains promotional materials.

Who this course is for:

Anyone who want to get started with APIs
Beginner developers who want to use APIs in their projects
QA engineers who want to learn how to use APIs

Introduction to REST APIs for Absolute Beginners

What you'll learn

Explore related topics

Course content

Introduction to APIs3 lectures • 21min

Building HTTP requests with Postman13 lectures • 1hr 15min

Working with REST APIs in Postman23 lectures • 1hr 26min

How to upload a file through an API (Giphy)10 lectures • 21min

Conclusion2 lectures • 2min

Requirements

Description

Who this course is for: