- The Azure Service Bus Topics is a loosely decoupled Pub/Sub PULL messaging model.
- The Azure Event Grid is a loosely decoupled Pub/Sub PUSH eventing model.
I do recommend to read the following document such as a foundation document for understanding Events, Data Points and Messages usage/concept, written by Clemens Vasters, Architect of the Azure Service Bus product:
also the other one, such as:
https://learn.microsoft.com/en-us/azure/event-grid/compare-messaging-services
Thanks
Roman