**Event-Driven Architecture**: A design pattern where services communicate by emitting and responding to events asynchronously.

**Key Components**:
* **Event Producer**: Generates events (e.g., a user uploads a file).  
* **Event Consumer**: Listens and reacts to events (e.g., a service processes the uploaded file).  
* **Message Broker**: Facilitates event delivery (e.g., Kafka, RabbitMQ).

**When to Use**:
* Applications needing real-time updates (e.g., chat apps, stock trading platforms).  
* Decoupled microservices to enhance scalability and maintainability.  
* Workflows with asynchronous tasks (e.g., order processing).