Docker and virtual machines (VMs) are both technologies used to isolate and manage software applications and services. However, they differ in several ways, including:
- Architecture: Docker is a containerization technology that operates at the application level, while virtual machines operate at the hardware level. Docker containers share the host operating system’s kernel and only isolate the application environment, while virtual machines run a separate operating system instance on top of a hypervisor.
- Resource usage: Docker containers use fewer system resources than virtual machines because they share the host operating system’s kernel and do not require a separate operating system instance. Virtual machines, on the other hand, require more system resources to run because they run a separate operating system instance.
- Boot time: Docker containers start up much faster than virtual machines because they only need to launch the application environment, while virtual machines need to start up a separate operating system instance.
- Isolation: Docker containers provide application-level isolation, while virtual machines provide hardware-level isolation. Docker containers share the host operating system’s kernel and may be more vulnerable to security threats that target the kernel, while virtual machines provide a stronger security boundary because they run a separate operating system instance.
- Portability: Docker containers are highly portable and can be easily moved between different host operating systems, while virtual machines may have compatibility issues when moved between different hypervisors.
In summary, Docker and virtual machines both provide isolation and management capabilities, but they differ in their architecture, resource usage, boot time, isolation level, and portability. Which one to choose depends on your specific use case and requirements.