gRPC is an open-source remote procedure call (RPC) framework initially developed by Google. It facilitates communication between distributed applications and services with high performance and speed. gRPC uses HTTP/2 as its transport protocol, enabling features like bidirectional streaming, flow control, header compression, and multiplexing requests over a single TCP connection. It supports multiple languages, making it suitable for polyglot environments. The framework leverages Protocol Buffers (ProtoBuf) as its interface definition language to define service methods and message formats in a language-neutral way. This allows developers to build, scale, and manage microservices with streamlined communication and improved efficiency.