What is Proxmox?
Proxmox is an open source virtualization software based on Linux. The software has a paid subscription, but can also be used for free. I myself use Proxmox for free and can use all functionalities. So with Proxmox you have the possibility to build a home server out of your old laptop or PC.
Proxmox is open source and gives me a lot of options to administer my virtual machines. Primarily, I use Proxmox to easily and quickly backup the virtual machines to my NAS using ProxmoxBackup. Since the VM’s or containers are not installed directly on a physical device, I can backup, shutdown or boot them individually at any time and dynamically adjust the CPU as well as RAM settings.