Virtualization

Hypervisor

Hypervisor is the piece of software that runs virtual machines. It allows to run several OS on a single physical machine. It's typically responsible to allocate resources and provide interface between the guest (the VM) and the host.

There is two types of hypervisor:

Type-1: Native / Bare-metal

• Hardware virtualization
• Sits between hardware and the VM

Type-2: Hosted

• Software virtualization
• Sits on top of the host's OS

Virtual Machines

• Pets type

Containerization

Containers is the principle to run processes, like applications, in an isolated environment. We call that OS-level virtualization.

Some characteristics:

• Lightweight and serverless: allow for fast build and deployment
• Don't have to embark an all OS
• Run natively on the machine
• Good for reproducibility, consistency and scaling
• Isolation at process level (less secure than VMs)
• Cattle type