Protocol Buffers (protobuf) are a language-neutral, platform-neutral, extensible mechanism for serializing structured data. They are used to define how data is structured, serialized, and transmitted between different systems or stored persistently. Protobufs are particularly useful in scenarios where data needs to be exchanged between applications written in different programming languages or running on different platforms. They offer advantages over other serialization formats like XML or JSON in terms of efficiency, speed, and code generation capabilities. The format uses a binary encoding, making it more compact and faster to parse than text-based formats. Protobufs are defined using a schema language, which specifies the structure of the data, including fields, data types, and relationships. From this schema, code can be generated in various programming languages (e.g., C++, Java, Python, Go) to easily serialize and deserialize data according to the defined structure. This ensures consistency and reduces the risk of errors during data exchange. Protocol Buffers are widely used in distributed systems, microservices architectures, and data storage applications.