Azure app service provides fully managed platform to run cloud applications i.e PAAS service . No need to create and manage any virtual servers. Its similar to AWS Elastic Beanstalk services. Database also you can run with Azure App service.Quickly build, deploy, and scale enterprise-grade web, mobile, and API apps running on any platform .
Azure App Service is an HTTP-based service for hosting web applications, REST APIs, and mobile back ends. You can develop in your favorite language, be it .NET, .NET Core, Java, Ruby, Node.js, PHP, or Python. Applications run and scale with ease on both Windows and Linux-based environments. For Linux-based environments, see App Service on Linux.
This is one of the most popular service in Azure . Many customers already started using in production . Particularly this service is more popular than in Amazon elastic beanstalk .
4 major categories of Azure App service
1. Web Apps
2. Web Apps for containers – dockers
3. Mobile Apps
4. API App
Important features
1. Supports all major programming language
2. No need to manage infrastructure
3. Supports Auto scaling
4. Easily can change App service plan
5. Supports Windows and Linux
6.Supports automated continuous deployments from Azure DevOps, GitHub, Docker Hub, VSTS and many other sources
7.Staging and multiple environments
8.Custom domain and SSL certificates
9.Meet major security compliance
10.Server-less environment
11.API and mobile features
12.App with DB
Reference Link : https://docs.microsoft.com/en-us/azure/app-service/app-service-web-overview