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

Summary

This video introduces REST, a popular communication standard for APIs used by most mobile and web applications. REST, which stands for REpresentational State Transfer, is a set of rules for building APIs. The video explains the basic structure of RESTful APIs, including the use of HTTP verbs (GET, POST, PUT, DELETE), status codes, statelessness, and resource organization with URIs. It also covers topics like pagination, versioning, and idempotency. REST is widely used because of its simplicity and scalability, though alternatives like GraphQL and gRPC exist.

Takeaways

• 🌐 REST is the most common communication standard for web and mobile applications to interact with servers.
• 🤖 API stands for Application Programming Interface, allowing two computers to communicate with each other.
• 📜 REST stands for REpresentational State Transfer and is not a specification but a set of rules for building web APIs.
• 🔗 RESTful APIs organize resources into unique URIs (Uniform Resource Identifiers) and group them by nouns, not verbs.
• ⚙️ RESTful APIs use HTTP methods like POST (create), GET (read), PUT (update), and DELETE (remove) to interact with resources.
• ✅ Proper RESTful APIs return HTTP status codes like 200 for success, 400 for client errors, and 500 for server errors.
• 🔄 Idempotency in APIs means that multiple identical requests have the same effect as a single request, except for certain cases like POST.
• 📦 Responses are usually formatted in JSON, and REST is stateless, meaning each request-response is independent.
• 📊 Pagination can be used in RESTful APIs when dealing with large amounts of data, using parameters like 'limit' and 'offset'.
• 📅 Versioning is essential in RESTful APIs to ensure backward compatibility and allow time for clients to adapt to new versions.

Q & A

What does REST stand for, and why is it important?

REST stands for REpresentational State Transfer. It is important because it provides a set of rules that have become the common standard for building web APIs since the early 2000s, enabling efficient communication between client and server over the Internet.

What is an API, and how is it used in the context of REST?

API stands for Application Programming Interface, and it allows two computers to communicate with each other. In the context of REST, APIs allow clients (like web and mobile apps) to interact with servers by sending HTTP requests and receiving responses.

What is a RESTful API, and can you provide some real-life examples?

A RESTful API is an API that follows the REST standard. Some real-life examples of RESTful APIs are Twilio, Stripe, and Google Maps.

How are resources organized in a RESTful API?

In a RESTful API, resources are organized into a set of unique URIs (Uniform Resource Identifiers). Resources are typically grouped by nouns, not verbs. For example, to access all products, the URI might be '/products' instead of '/getAllProducts'.

What are the main HTTP methods used in RESTful APIs, and what do they do?

The main HTTP methods in RESTful APIs are POST, GET, PUT, and DELETE. POST is used to create a new resource, GET is for reading data, PUT is for updating an existing resource, and DELETE is for removing a resource.

What does CRUD stand for in the context of RESTful APIs?

CRUD stands for Create, Read, Update, and Delete. These operations correspond to the HTTP methods POST (Create), GET (Read), PUT (Update), and DELETE (Delete).

What role does JSON play in RESTful APIs?

In RESTful APIs, the request and response bodies often contain data encoded in JSON (JavaScript Object Notation). JSON is used to format the data payload being sent between client and server.

What are HTTP status codes, and what do different ranges of codes indicate?

HTTP status codes tell the client the outcome of their request. Codes in the 200 range mean success, the 400 range indicates client errors (e.g., incorrect syntax), and the 500 range indicates server errors (e.g., service unavailable).

What does it mean for an API to be stateless, and why is this important?

A stateless API means that each request from a client contains all the necessary information, and no session or state is stored between requests. This allows for easier scaling and more predictable behavior in web applications.

Why is API versioning important, and how can it be implemented?

API versioning is important to provide backward compatibility when introducing breaking changes. It can be implemented by prefixing the version number in the URI (e.g., '/v1/products'), allowing users to migrate to new versions over time.