The Proxmox update keeps a node up to date with the latest stable packages, patches security vulnerabilities, and introduces new features. Each node checks for the latest updates and alerts administrators through e-mails if there are any available updates. It is vital to keep all Proxmox nodes up to date especially when security patches are released. Proxmox developers are very prompt to close vulnerabilities through updates in a timely manner.
The number and nature of updates varies depending on your Proxmox subscription level. For example, a Proxmox free version without a subscription receives the most up-to-date stable updates while a node with a subscription level receives updates, which are not so cutting edge and go through an additional layer of testing. Delaying the new package releases for subscription levels creates a buffer to address any issues that may have not been identified during the initial release.
This is not to say that a node without a subscription...