Web Parts and App Part Pages
One of the key features of SharePoint is the ability to customize the look and functionality of pages with web parts. A web part is a reusable component that can display content or information from various sources, such as lists and libraries, or external sources such as the Microsoft Graph API. The web part can also act as a user interface and create and update data.
An app part is a special representation of a web part. When the web part can be added like a component to a page, the app part is the whole page, such as a single-page application (SPA). A single web part can either be a component on a page or act like an SPA with the same code base. The behavior is controlled with a SharePoint Framework solution setting.
Web parts can also be used inside Microsoft Teams, where they can be added as an application. A web part can be hosted as a tab in Microsoft Teams channels, or as a personal application, which is targeted to a user and located in the...