Upgrade and Update
Upgrading to a new version of SharePoint? The first step in any upgrade process is to learn about the process itself so that you can plan and prepare appropriately. These articles help you understand how the SharePoint upgrade process works. These articles also include overviews of how to upgrade service applications.
Applying updates to a current version? Microsoft periodically releases software updates for SharePoint. These articles and related resources provide information about the software update process for SharePoint Server 2013, SharePoint Server 2016, and SharePoint Server 2019.