Apps for SharePoint are self-contained pieces of functionality that extend the capabilities of a SharePoint website. Basically, in SharePoint, the application can be hosted by 3 types.
SharePoint Hosted Application
Provide basic resource into the app or web, such as HTML/CSS/JS files etc. No Server-side code runs under SharePoint-Hosted application.
Auto Hosted Application
Auto Hosted apps for SharePoint are Cloud-Hosted apps whose remote computers are provisioned and...