KVM

• KVM

A KVM switch (with KVM being an abbreviation for "keyboard, video and mouse") is a hardware device that allows a user to control multiple computers from one or more[1] keyboard, video monitor and mouse. Although multiple computers are connected to the KVM, typically a smaller number of computers can be controlled at any given time. Modern devices have also added the ability to share other peripherals like USB devices and audio.
https://en.wikipedia.org/wiki/KVM_switch

• What is KVMoIP?

KVMoIP (Keyboard, Video, Mouse) over IP allows IT administrators to remotely manage their UK dedicated box even when their usual remote access software (SSH, RDP, VNC etc) is no longer functioning. As long as the dedi server is powered on and can get past BIOS post, administrators will have full BIOS-level access.
https://www.racksrv.com/portal/knowledgebase/10/What-is-KVMoIP.html

• The Dell Remote Access Controller or DRAC is an out-of-band management platform on certain Dell servers. The platform may be provided on a separate expansion card, or integrated into the main board; when integrated, the platform is referred to as iDRAC.

It uses mostly separate resources to the main server resources, and provides a browser-based or command-line interface (or both) for managing and monitoring the server hardware
https://en.wikipedia.org/wiki/Dell_DRAC