"Have you ever been building SPFx solutions, and wanted to use different settings for different environments? This web part allows you to easily swap between different environment settings, and even add your own custom settings."
"name":"Build your first SharePoint client-side web part",
"description":"Client-side web parts are client-side components that run in the context of a SharePoint page. Client-side web parts can be deployed to SharePoint environments that support the SharePoint Framework. You can also use modern JavaScript web frameworks, tools, and libraries to build them.",