What are the differences between event systems in azure (Study of AZ 204)

1. **Azure Event Hubs**: This is a big data streaming platform and event ingestion service that can consume millions of events per second, process them in real-time, store the data for further processing or analysis, and enable parallel processing using multiple consumers. Event Hubs supports various input formats like Kafka, AMQP (Advanced Message Queuing Protocol), and REST APIs.

2. **Azure Service Bus**: This is a message broker service that enables building loosely coupled distributed applications using queueing or topic-subscription patterns, ensuring reliable and asynchronous messaging between components. Service Bus Queues can store messages for an extended period (up to 7 days), while Topics provide a publish-subscribe model with multiple consumers that receive the same message.

3. **Azure Event Grid**: This is an event routing service designed to handle complex events and connect applications together, enabling them to respond in real-time when specific actions occur. With Event Grid, you can create event subscriptions based on custom topics or system events and route these messages directly to Azure Functions, App Services, Logic Apps, or any other compatible service.

4. **Azure LogicApps**: This is a cloud workflow automation platform that enables the development of complex event-driven applications using visual flow design tools and prebuilt connectors to various services (including Azure Functions, Power BI, Office 365, Dynamics CRM Online, among others). LogicApps provides a simple and powerful way to build workflows triggered by specific events or conditions.

5. **Azure Functions**: This is a serverless compute service that allows you to run code in response to various triggers, including HTTP requests, queue messages (from Service Bus or Event Hubs), blob storage changes (in Azure Blob Storage), and timer events. Functions are ideal for processing small pieces of code in a scalable, event-driven manner.

Each of these Azure services offers unique features and benefits that cater to various use cases within your application architecture. When designing an event-driven solution, consider the specific requirements for reliability, scalability, latency and cost when choosing between these services or combining them as needed.