What is message?

A message is a piece of information that one computer, program, or device sends to another. It can be as simple as a text string like “Hello” or as complex as a structured data packet containing many fields. In tech, messages are the basic way different parts of a system talk to each other.

Let's break it down

  • Sender: The part that creates the message (e.g., a user’s app, a server, a sensor).
  • Message content: The actual data being transferred (text, numbers, files, commands).
  • Transport: The method used to move the message (HTTP request, TCP packet, Bluetooth, etc.).
  • Receiver: The part that gets the message and processes it (another app, a database, a device).
  • Acknowledgment (optional): A reply that tells the sender the message was received correctly.

Why does it matter?

Messages let separate systems work together without being tightly linked. This makes software easier to build, update, and scale. By sending messages, you can:

  • Share data in real time (chat apps, live dashboards).
  • Trigger actions across different services (e.g., an order placed triggers inventory and shipping updates).
  • Keep systems reliable-if one part fails, messages can be stored and retried later.

Where is it used?

  • Web APIs: Browsers send HTTP messages to servers to request pages or data.
  • Messaging apps: WhatsApp, Slack, and email use messages to deliver text, images, and files.
  • IoT devices: Sensors send telemetry messages to the cloud.
  • Microservices: Services communicate via message queues like RabbitMQ or Kafka.
  • Operating systems: Processes exchange messages through sockets or inter‑process communication (IPC).

Good things about it

  • Decoupling: Senders and receivers don’t need to know each other’s internal details.
  • Scalability: You can add more receivers or senders without redesigning the whole system.
  • Reliability: Messages can be stored, retried, or routed around failures.
  • Flexibility: Different transport methods (HTTP, MQTT, WebSockets) can be chosen based on needs.
  • Asynchrony: Systems can continue working while waiting for a response, improving performance.

Not-so-good things

  • Complexity: Setting up reliable messaging (queues, brokers, retries) adds extra components to manage.
  • Latency: Some message systems introduce delays, which may be problematic for ultra‑fast requirements.
  • Debugging difficulty: Tracing a problem across multiple asynchronous messages can be harder than in a simple direct call.
  • Security concerns: Messages traveling over networks need encryption and authentication to prevent interception or tampering.
  • Potential for message loss: If not configured correctly, messages can be dropped, leading to data inconsistency.