Explain the difference between containerization and virtualization.

Containerization and virtualization are technologies for isolating and managing application runtime environments, but they operate at different levels and have different characteristics.

Virtualization creates full virtual machines (VMs), each containing its own operating system on top of a hypervisor. This allows running different OSes on a single physical server. Virtual machines are isolated from each other but require significant resources (CPU, memory, disk) since each OS runs separately.

Containerization uses OS kernel features (such as Linux namespaces and cgroups) to isolate processes and resources. Containers share the host OS kernel but have their own filesystem, network, and processes. This makes containers lighter and faster to start compared to VMs.

Key differences:

• Resources: VMs are heavier, containers are lighter and faster.
• Isolation: VMs are isolated at the OS level, containers at the process level.
• Flexibility: VMs can run different OSes, containers are only compatible with the host.

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

In summary, containerization is suitable for quick and lightweight application packaging, while virtualization provides full isolation and the ability to run different OSes on a single server.