What is the difference between virtualization and containerization?

Virtualization and containerization are application isolation technologies, but they work differently.

Virtualization creates full virtual machines with their own operating system kernel. Each VM contains a guest OS, which requires significant resources (memory, CPU). This provides strong isolation but reduces resource utilization efficiency.

Containerization uses the host kernel's capabilities (e.g., cgroups and namespaces in Linux) to isolate processes without running a separate OS. Containers are lighter and faster to start, consume fewer resources, but the isolation is less strict than in VMs.

Example: Docker is a popular containerization tool, while VMware or VirtualBox are examples of virtualization.