How is message passing implemented in RabbitMQ system?

In RabbitMQ, message transmission occurs through exchanges and queues. The process looks like this:

1. Producer sends a message to an exchange.
2. Exchange routes the message to one or more queues according to rules (binding).
3. Consumer subscribes to the queue and receives messages from it.

Thus, messages are not sent directly from producer to consumer but pass through an exchange and a queue, which provides flexibility and reliability.

Example of sending a message in RabbitMQ using C# with the RabbitMQ.Client library:

var factory = new ConnectionFactory() { HostName = "localhost" };
using(var connection = factory.CreateConnection())
using(var channel = connection.CreateModel())
{
    channel.QueueDeclare(queue: "hello", durable: false, exclusive: false, autoDelete: false, arguments: null);

    string message = "Hello RabbitMQ!";
    var body = System.Text.Encoding.UTF8.GetBytes(message);

    channel.BasicPublish(exchange: "", routingKey: "hello", basicProperties: null, body: body);
    Console.WriteLine(" [x] Sent {0}", message);
}