What is the difference between containerization and virtualization?

Containerization and virtualization are isolation technologies, but with different architectures:

• Virtualization creates full virtual machines with their own guest OS on top of a hypervisor. Each VM contains an OS kernel, which requires more resources.

• Containerization uses the capabilities of the host OS kernel (for example, namespaces and cgroups in Linux) to isolate processes and resources. Containers share the OS kernel but have separate process spaces and file systems.

Main differences:

Parameter	Virtualization	Containerization
Resources	Heavier, separate OS kernel	Lightweight, shared OS kernel
Startup time	Minutes	Seconds or milliseconds
Isolation	Full (guest OS)	Process-level isolation
Portability	High (different OSes)	Depends on the host OS

Containers are convenient for microservices and rapid deployment, virtualization is suitable for running different OSes and more strict isolation.