- Non-Isolated Mode: Your function code runs in the same process as the Azure Functions runtime. It offers better performance and simplicity.
- Isolated Mode: Your code runs in a separate worker process. It communicates with the runtime via gRPC, providing more flexibility and compatibility with modern .NET features like custom dependency injection and middleware.

you may want to review this:

https://wiseservices.co.uk/post/b98a1606-487b-4743-9862-af1d232485d4

or this:

https://learn.microsoft.com/en-us/azure/azure-functions/dotnet-isolated-in-process-differences