What is the difference between REST and gRPC in microservices?

REST (Representational State Transfer) uses HTTP with JSON or XML payloads. It is human-readable, easy to debug with standard tools like curl and browsers, and widely understood. However, JSON parsing is relatively slow and verbose. gRPC is Google's high-performance Remote Procedure Call framework that uses Protocol Buffers (binary serialization) over HTTP/2. gRPC is significantly faster and more bandwidth-efficient than REST, supports strongly-typed contracts via .proto files, and enables bidirectional streaming. gRPC is ideal for internal service-to-service communication where performance matters, while REST is preferred for public-facing APIs where broad client compatibility is needed.