Docker versus virtual machine comparison¶
Docker containers and traditional virtual machines (VMs) are both technologies used to isolate applications and their dependencies, but they differ fundamentally in their architecture and resource management.
Architecture and Resource Isolation¶
Virtual Machines operate by including a full operating system alongside the application. A system virtualizer (often called a Hypervisor) sits between the host hardware and the guest operating systems, allowing multiple VMs to run on a single physical server.^[600-developer__k8s.md]
In contrast, Docker containers share the host machine's operating system kernel. They isolate the application processes from the host and from each other, but they do not require a full guest OS for each instance.^[600-developer__k8s.md]
Performance and Overhead¶
Because Docker containers do not need to boot a separate operating system kernel, they are significantly more lightweight than virtual machines. VMs include the entire OS, making them heavier in terms of resource usage and startup time.^[600-developer__k8s.md]