Protocol Buffers (protobuf) is Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data. It's like XML, but smaller, faster, and simpler.
Key Features:
- Efficient: Smaller size and faster than XML/JSON
- Type-safe: Strongly typed with schema validation
- Versioning: Forward and backward compatibility
- Multi-language: Support for many programming languages
- RPC Support: Built-in support for gRPC
Common Use Cases:
- Microservices communication (gRPC)
- Data storage and serialization
- Configuration files
- Network protocols
- Inter-process communication
Proto3 vs Proto2:
- Proto3: Simplified syntax, all fields optional by default
- Proto2: Explicit required/optional/repeated, default values
Field Types:
Common scalar types: double, float, int32, int64, uint32, uint64, sint32, sint64, fixed32, fixed64, sfixed32, sfixed64, bool, string, bytes