Microsoft announced Azure Container Apps, a new service for running serverless containers in the cloud. This appears to be similar to the Container Instances service, which is also for deploying fully-managed containers.
What are the key differences between these two services?
That's a good question and I've asked the team about it because it wasn't clear to me either.
In summary: if you'll spin up multiple container (e.g. front end / backend / database), Azure Container Apps is a better choice as it comes with Dapr and it will auto retry the requests and add some telemetry data.
If you just need long running jobs or you don't need multiple containers to communicate with each other, you can go with Azure Container Instances.
Azure Container Instances
Azure Container Apps
source: https://docs.microsoft.com/en-us/azure/container-apps/compare-options
In a nutshell, workloads on ACI are usually started and stopped by some kind of process or trigger and are usually short-lived while workloads on ACA are usually long-running processes like a Web app.