Explaining gRPC and REST to a Layperson

In today’s interconnected world, client applications and server applications often need to work together, even if they are on different machines. Today, we will explore two different communication protocols: gRPC and REST. We'll use a simple analogy to explain how they function and their differences, making these concepts easier to understand for anyone, even a child.

Understanding Client and Server Applications

Imagine you have a robot (the client application) that you want to instruct to perform a task. You can give it simple commands, like 'put on shoes' or 'mow the lawn'. This robot listens to you and performs the task accordingly. When you, the owner (the server application), are at home, you can directly command the robot. However, what if you were on a beach in Acapulco, a month later? You can still command your robot, but now you need to use a different method. Let's explore this further using gRPC and REST.

gRPC: Direct Method Calls, Just Like a Robot Sharing Your Mind

In gRPC, think of the robot’s brain as an extension of your own. Instead of giving a simple command like 'mow the lawn', you can directly call the method on the robot’s brain as if it were your own. This makes it much easier to create and maintain distributed applications and services, as the client and server can interact seamlessly, as if they were local objects. For example, instead of saying 'mow the lawn', you can command the robot to 'mow()'. You don’t need to specify how it should mow; you just call the method, and the robot does the work. This is the power of gRPC – it simplifies distributed computing by allowing direct method calls between applications on different machines.

REST: Believe in Good Old Letters and Words to Communicate

REST, on the other hand, is more like writing a letter to your robot. The robot understands specific formats (URIs) and can interpret these to perform tasks. Here’s a step-by-step breakdown of how REST works: tIdentify Object Model: Think of the lawn as a resource that needs to be mowed. In REST, resources are identified by URLs. tCreate Model URIs: You create a URI that points to the lawn. For instance, http://robot/ZNobA/lawn tDetermine Representations: You need to describe how the lawn looks before and after mowing. This is the representation of the resource. tAssign HTTP Methods: HTTP methods like GET, POST, PUT, DELETE are used to interact with the resource. For example, you can use POST to send instructions to mow the lawn. So, to command the robot to mow the lawn, you would send a POST request to the URI http://robot/ZNobA/lawn, containing instructions about how to mow the lawn.

The Power of Choice: gRPC vs REST

Both gRPC and REST have their strengths and use cases. Here’s a simple analogy to show their differences:

Imagine you are at home and your kid needs to mow the lawn. You can command him directly, as in gRPC, or you can write a detailed letter (REST) with instructions for him to follow. Both methods will result in a well-mowed lawn, but the process and the level of detail required are different.

Conclusion

In summary, gRPC is like a direct line of communication, where commands are sent and executed in real-time. REST, on the other hand, is more like written instructions that require parsing and interpretation. Both are powerful tools, and the best choice depends on the specific needs of your application.

Additional Reading

If you want to dive deeper into these topics, there are plenty of resources online. Here are a few more articles to explore: tWhy gRPC is Better Than REST tUnderstanding RESTful API Design tgRPC Concepts and Concepts Happy coding!