What gRPC is
gRPC is a high-performance, open-source framework for communication between software services, originally developed by Google. The RPC stands for Remote Procedure Call, an old idea that lets a program call a function on another computer as if it were a local function. gRPC modernizes this concept for today's distributed systems and has become especially popular for connecting the many small services inside large applications.
The remote procedure call idea
In a REST API, you think in terms of resources and HTTP methods. gRPC takes a different mental model: you define the functions a service offers, and other services call those functions directly, passing in arguments and getting results back, just like calling any ordinary function. This can feel more natural to developers, because the network communication is largely hidden behind what looks like a normal function call.
Protocol Buffers
gRPC uses Protocol Buffers, often called protobuf, to define its functions and to package the data they exchange. You write a simple definition file describing the available methods and the structure of their messages, and tools generate matching code in many programming languages. The data is sent in a compact binary format rather than text, which is smaller and faster to process than the JSON that REST typically uses.
Built on HTTP/2
gRPC runs on HTTP/2, a modern version of the web's protocol that allows many requests to share a single connection efficiently. This enables powerful features such as streaming, where data can flow continuously in one or both directions rather than in single request-and-response pairs. Combined with the compact binary format, this makes gRPC very fast and well suited to heavy communication between services.
gRPC versus REST
gRPC and REST solve similar problems differently. gRPC is faster, strongly typed, and excellent for internal communication between services, especially in microservice systems. REST is simpler, human-readable, works directly in browsers, and is better for public APIs that many outside developers will use. The two are not rivals so much as tools for different jobs, and many systems use REST at the edge and gRPC internally.
The bottom line
gRPC lets services call each other's functions directly using compact Protocol Buffers over fast HTTP/2 connections, making it a high-performance choice for internal and microservice communication. It trades the browser-friendly simplicity of REST for speed, streaming, and strong typing. Understanding it explains how the many pieces of a large modern application talk to each other quickly behind the scenes.
Related on Skillo
See also: What is GraphQL? Explained, What is a microservice architecture?.
Sources
Published date reflects the original event date (2026-10-23). This article is original Skillo editorial written from the sources above; facts were verified in September 2026.
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