Differences:

• Triggers: Azure Functions offer additional out-of-the-box triggers, making them more versatile for event-driven scenarios.

• Scalability: Functions automatically scale with Consumption or Premium plans, while App Service requires manual scaling configuration

Scalability:

• Consumption/Premium Plans: Functions scale automatically based on demand, without additional configuration

• App Service Plan: Hosting Functions in an App Service Plan can limit scalability if scaling is not configured

For more details, refer to the official documentation