A hypervisor is software that allows one physical computer (server) to run multiple virtual machines (VMs) at the same time.
There are two type of hypervisor :
- Bare Metal
- Hosted on OS
Mostly companies will use either VMware, Nutanix, Windows Hyper-V or etc
There are so many including paid and open-source

(Bare-metal)
Nutanix is a technology company that provides a platform to run virtual machines, storage, and networking in a simple, unified system.
It is best known for hyper-converged infrastructure (HCI), which means:
It combines compute + storage + virtualization into one easy-to-manage platform.
But it need its support hardware for it. Need to check with disti for.

(Bare-metal)
VMware is a company and a technology platform that allows you to run multiple virtual machines (VMs) on a single physical server now own by Broadcom in November 2023.
It so simple to do installation which required to install VMware ESXi
For manage multiple device required installation VMware vCenter.
Before this VMware also provide free version ESXI which can operate normally but backup

(Bare-metal)
Proxmox VE (Virtual Environment) is a free, open-source virtualization platform used to run virtual machines and containers on a server.
Most popular using for
Home labs
Small businesses
Learning virtualization
Even company also use it for small system development
Another alternative for Proxmox is

(Bare-metal)
XCP-ng is a free, open-source virtualization platform (hypervisor) used to run virtual machines (VMs) on physical servers.
It provides Built-in backup support (with Xen Orchestra)
Active community