Docker

• Docker is container-based technology and containers are just user space of the operating system.
• Docker is an open platform for developing, shipping, and running applications.
• Docker enables you to separate your applications from your infrastructure so you can deliver software quickly.

Virtual Machine

• A virtual machine is a system that acts exactly like a computer.
• A Virtual Machine, on the other hand, is not based on container technology. They are made up of user space plus kernel space of an operating system.
• Under VMs, the server hardware is virtualized.

Difference between Docker vs VM

• Well, the significant differences are their operating system support, security, portability, and performance.

Some Other differences are -

For Virtual machine ,

• Each VM runs in its own OS
• Hardware-level virtualization
• Each VM has a separate OS
• It works Using Hypervisor (A medium between VM and host OS. It manage the VM)

For Docker ,

• All containers share the host OS.
• OS-level virtualization ( Share the host OS kernel )
• Each container can share OS
• It works using Docker Engine ( Client-server application that for building and containerizing your applications )

Advantages of Virtual Machines over Docker Containers

• The tools associated with a virtual machine are easier to access and simpler to work with. Docker has a more complicated tooling ecosystem, that consists of both Docker-managed and third-party tools.
• Docker uses to optimize resource usage comes at the cost of security. Virtual machines have the advantage because they keep the OS separate from the hardware to minimize any risk of damage.
• The tools associated with a virtual machine are easier to access and simpler to work with. Docker has a more complicated tooling ecosystem, that consists of both Docker-managed and third-party tools.

Advantages of Docker Containers over Virtual Machines

• Docker containers are process-isolated and don’t require a hardware hypervisor. This means Docker containers are much smaller and require far fewer resources than a VM.
• More Efficient.
• Docker is fast. Very fast. While a VM can take at least a few minutes to boot and be dev-ready, it takes anywhere from a few milliseconds to (at most) a few seconds to start a Docker container from a container image.