A Virtual Machine (VM) is an emulation of a computer system. It is based on computer architectures and provides the functionality of a physical computer. VMs run on top of a hypervisor, which manages the hardware resources, allowing multiple OS instances to run simultaneously on a single physical host.
VMs provide strong hardware-level isolation, making them more secure for multi-tenant environments than containers. However, they include a full OS guest (GBs in size), which means slower boot times and higher resource overhead compared to containerization.
Virtual Machines remain the foundational substrate of the cloud (e.g., EC2 instances, KVM nodes). While we prefer containers for application workloads, we recognize VMs as the necessary "hard" boundary for security isolation and the hosting layer for our Kubernetes clusters. They are infrastructure, not application artifacts.