Q1. What is gRPC?

1. Simple metaphor gRPC = express highway for data — faster and more structured than REST roads.

2. Deep dive theory

• Google Remote Procedure Call.
• Uses HTTP/2 + Protobuf for serialization.
• Supports bidirectional streaming.
• Strongly typed contracts.

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Q2. How is gRPC different from REST?

1. Simple metaphor

• REST = postal service (JSON text, slower).
• gRPC = phone call (binary, faster, bidirectional).

2. Deep dive theory

• REST: JSON over HTTP/1.1, text-heavy.
• gRPC: Protobuf over HTTP/2, binary, smaller messages.
• REST: simple, widely adopted.
• gRPC: faster, but requires code generation + tooling.

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Q3. What is Protobuf in gRPC?

1. Simple metaphor Protobuf = compressed recipe card — short, structured, easy to read by machines.

2. Deep dive theory

• Protocol Buffers = serialization format.
• Compact binary representation.
• Contract-first → .proto defines service + messages.

syntax = "proto3";

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply);
}

message HelloRequest {
  string name = 1;
}

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Q4. What are the communication types in gRPC?

1. Simple metaphor Think of gRPC calls like conversations:

• Unary = single Q\&A.
• Server streaming = waiter brings multiple dishes after one order.
• Client streaming = customer gives multiple orders, then gets one bill.
• Bi-directional = both sides chat freely.

2. Deep dive theory

• Unary.
• Server streaming.
• Client streaming.
• Bi-directional streaming.

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Q5. What is HTTP/2 and why does gRPC use it?

1. Simple metaphor HTTP/1.1 = one-lane road. HTTP/2 = multi-lane expressway → multiple requests simultaneously.

2. Deep dive theory

• Multiplexed streams.
• Header compression.
• Binary framing.
• Server push.