TubeSum ← Transcribe a video

What Is REST API? Examples And How To Use It: Crash Course System Design #3

Transcribed Jun 16, 2026 Watch on YouTube ↗
Beginner 3 min read For: Software developers, system designers, and technical learners new to APIs.
1.4M
Views
36.2K
Likes
393
Comments
118
Dislikes
2.7%
📈 Moderate

AI Summary

REST is the most common communication standard between computers over the internet. This video explains what an API is, defines REST (REpresentational State Transfer), and covers key principles like statelessness, resource URIs, HTTP verbs, status codes, pagination, and versioning. It concludes by noting REST’s simplicity and comparing it briefly to GraphQL and gRPC.

[0:07]
REST as the common standard

REST is the most popular API standard used by mobile and web applications to talk to servers.

[0:21]
Definition of API and REST

API is a way for two computers to talk; REST stands for REpresentational State Transfer and is a set of rules for building web APIs.

[0:48]
RESTful API examples

Examples include Twilio, Stripe, and Google Maps.

[1:04]
Resource URIs and nouns

Resources are organized by URIs and should be grouped by noun, not verb (e.g., /products not /getAllProducts).

[1:49]
HTTP verbs

POST creates, GET reads, PUT updates, DELETE removes (CRUD).

[2:10]
Request and response structure

Requests may contain an optional JSON body; responses include an HTTP status code and optional data payload.

[2:38]
HTTP status code levels

2xx success, 4xx client error (e.g., bad syntax), 5xx server error (e.g., service unavailable).

[3:05]
Idempotency and retrying

Idempotent APIs (GET, PUT, DELETE) allow safe retries; POST is typically not idempotent.

[3:38]
Statelessness

REST should be stateless—each request/response is independent, making scaling easier.

[4:05]
Pagination and versioning

Use pagination (limit/offset) for large datasets; version APIs (e.g., /v1/products) for backward compatibility.

REST remains widely used because it is simple, effective, and good enough for most applications. Other options like GraphQL and gRPC exist and will be compared in future videos.

Mentioned in this Video

Study Flashcards (5)

What does REST stand for?

easy Click to reveal answer

REpresentational State Transfer

0:27

List the four HTTP verbs used in CRUD and their meanings.

medium Click to reveal answer

POST (create), GET (read), PUT (update), DELETE (remove)

1:49

What does a 404 status code indicate?

medium Click to reveal answer

Not explicitly stated, but 4xx codes mean client error. 404 specifically means 'not found' (common knowledge). In the video, 4xx means 'something was wrong with our request' (e.g., incorrect syntax).

2:45

What is the key benefit of statelessness in REST?

easy Click to reveal answer

It makes web applications easy to scale.

3:38

Why is a POST request usually not idempotent?

hard Click to reveal answer

Because making multiple identical POST requests can create multiple resources, unlike GET, PUT, or DELETE.

3:05

💡 Key Takeaways

💡

Why REST is popular

Defines REST as the de facto standard for web APIs since the early 2000s.

0:14
⚖️

URI naming convention

Concrete rule: group resources by noun, never verb.

1:10
📊

HTTP status code usage

Clear explanation of 2xx/4xx/5xx codes and their meaning for API behavior.

2:38
⚖️

Statelessness as scaling enabler

Identifies the critical architectural property that makes REST easy to scale.

3:38

✂️ Creator Tools: Viral Hooks

AI-generated clip ideas for Shorts based on the transcript

No viral clips found for this video, or they are still being generated.

[00:07] REST is the most common communication standard 

[00:14] is it so popular? Let's take a look. API stands 

[00:21] a way for two computers to talk to each other. 

[00:27] web applications to talk to the servers is called 

[00:34] It is a mouthful. What does that mean? REST is not 

[00:41] has been the common standard for building web API 

[00:48] standard is called a RESTful API. Some real-life 

[00:56] Let's look at the basics of REST. A RESTful API 

[01:04] Uniform Resource Identifiers. The URIs 

[01:10] on a server. Here are some examples. The resources 

[01:19] get all products should be slash products and not 

[01:27] resource by making a request to the endpoint for 

[01:34] specific format, as shown here. The line contains 

[01:41] The URI is preceded by an HTTP verb which tells 

[01:49] A POST request means we want to create a 

[01:55] the data about an existing resource. A PUT is 

[02:02] for removing an existing resource. You might have 

[02:10] In the body of these requests, there could be 

[02:15] a custom payload of data, usually encoded in 

[02:23] and formats the result into a response. The first 

[02:31] to tell the client what happened to the request. 

[02:38] HTTP status codes. The 200-level codes mean the 

[02:45] something was wrong with our request. For example 

[02:52] level, it means something went wrong at the server 

[02:59] A well-behaved client could choose to retry a 

[03:05] said "could choose to retry" because some actions 

[03:12] when retrying. When an API is idempotent, making 

[03:19] as making a single request. This is usually not the 

[03:26] The response body is optional and could contain 

[03:34] There's a critical attribute of 

[03:38] A REST implementation should be stateless. It 

[03:44] information about each other, and every request 

[03:50] This leads to web applications that are easy to 

[03:57] to discuss to round out a well-behaved RESTful API. 

[04:05] use pagination. A common pagination scheme 

[04:12] an example. If they are not specified, the server 

[04:20] versioning of an API is very important. Versioning 

[04:27] compatibility, so that if we introduce breaking 

[04:33] can get enough time to move to the next version. 

[04:40] straightforward is to prefix the version before 

[04:48] RESTful API is simple and effective when 

[04:54] choice for all companies, but it is simple and 

[05:00] There are other popular API options like GraphQL 

[05:09] separate videos. If you would like to learn more about system 

[05:14] Please subscribe if you learned something new. 

⚡ Saved you time reading this? Transcribe any YouTube video for free — no signup needed.