Besides the dist-upgrade command, there is another option available for upgrade:

# apt-get upgrade  

This is also the standard Debian-based Linux distribution command. However, there is a big difference between these two commands.

The apt-get upgrade command will only update the already installed packages without installing any new ones or making significant changes to the packages, such as removing them. This also will not satisfy any dependency issues. If any packages require dependencies to be resolved, this command will simply leave them alone. The main benefit of this package is that it will very rarely break the system. On the downside, it also will not update or patch everything that is necessary to bring a node up to date.

The apt-get dist-upgrade command, on the other hand, will upgrade all the packages and remove any unneeded packages dictated by the package maintainer. This command will also intelligently satisfy almost all the required dependencies for a package being updated or marked for a new installation.

Based on the previous explanation of these two update commands, we can see that both of these commands have advantages and disadvantages. But to keep a Proxmox node up to date, the apt-get dist-upgrade command seems to be the right way to go. Proxmox is not just another Linux distribution, but a highly specialized hypervisor. So packages that are included in a distribution are carefully chosen by Proxmox developers. Also, there is no mention of the apt-get upgrade command anywhere in the Proxmox wiki.