RPC vs. REST Overview
Understand the fundamental differences and use cases between Remote Procedure Calls (RPC) and Representational State Transfer (REST).
RPC vs. REST Overview is a free gRPC & High Performance APIs lesson on CoddyKit — lesson 3 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the gRPC & High Performance APIs learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
API Communication Patterns
APIs are how software systems talk — requesting data or actions remotely. Let's explore two fundamental communication styles: REST and RPC.
What is REST?
REST is an architectural style that treats everything as a resource — a user, a product — that you act on with standard HTTP methods like GET and POST.
Key Principles of REST
REST rests on a few principles: resources at unique URLs, standard HTTP methods, stateless requests, and a clean client-server separation.
REST in Practice
In REST, you map actions to HTTP methods: GET /users/123 to read, POST /users to create, PUT /users/123 to update. Responses are usually JSON.
What is RPC?
RPC (Remote Procedure Call) is about calling a function on a remote server as if it were local. It centers on actions, not resources.
Key Principles of RPC
RPC focuses on procedures: the API exposes specific functions like getUserById, a client invokes them, and a strict contract (like Protobuf) defines the shapes.
Simulating an RPC Call
In RPC you call a function with arguments and get a result. This snippet simulates calling a remote getUserDataById — over a network in a real system.
public class RpcClient {
public static void main(String[] args) {
System.out.println("Attempting to call remote procedure...");
// In a real RPC system, this would be a network call
String userData = getUserDataById(123);
System.out.println("Received user data: " + userData);
}
// This simulates a remote procedure call
private static String getUserDataById(int userId) {
// Imagine this method talks to a server
return "{id: " + userId + ", name: 'Alice'}";
}
}Core Difference: Focus
The core split is focus: REST centers on nouns (resources you GET), while RPC centers on verbs (functions you call). That shapes how you design each API.
When to Use Which?
Pick by need: REST suits CRUD, public APIs, browsers, and easy caching. RPC wins for internal microservices, high performance, and strict typed schemas.
Knowledge Check: REST vs. RPC
Which of the following statements accurately describe differences between REST and RPC?
Recap: REST vs. RPC
Two styles, recapped: REST is resource-oriented over HTTP, great for CRUD and public APIs; RPC is action-oriented, great for high-perf internal services.
Frequently asked questions
Is the “RPC vs. REST Overview” lesson free?
Yes — the full text of “RPC vs. REST Overview” is free to read here on the web, and the gRPC & High Performance APIs course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the gRPC & High Performance APIs course, upgrade to CoddyKit PRO.
What will I learn in “RPC vs. REST Overview”?
Understand the fundamental differences and use cases between Remote Procedure Calls (RPC) and Representational State Transfer (REST). You practise gRPC & High Performance APIs with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start gRPC & High Performance APIs?
No prior experience is required. gRPC & High Performance APIs on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “RPC vs. REST Overview” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this gRPC & High Performance APIs lesson?
Yes. Every gRPC & High Performance APIs lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.