The document discusses building SPFx solutions for SharePoint 2019. It provides an overview of the SharePoint Framework, how it supports client-side web parts and extensions in SharePoint 2019. It outlines considerations for the development environment including using the latest SPFx version and targeting SharePoint 2019. It also notes capabilities not supported like hub sites. The document then provides steps to set up the development environment including installing NodeJS, a code editor, Yeoman, Gulp and generating an SPFx project targeting SharePoint 2019.