Containers vs Virtual Machine vs Docker

Container

Using containers, everything required to make a piece of software run is packaged into isolated containers. Unlike VMs, containers do not bundle a full operating system - only libraries and settings required to make the software work are needed. This makes for efficient, lightweight, self-contained systems and guarantees that software will always run the same, regardless of where it’s deployed. Docker is an example of container technology, there are many other likes containerd, CRI-O etc

Virtual Machine(VM'S)

Virtual machines (VMs) are an abstraction of physical hardware turning one server into many servers. The hypervisor allows multiple VMs to run on a single machine. Each VM includes a full copy of an operating system, one or more apps, necessary binaries and libraries - taking up tens of GBs. VMs can also be slow to boot.

Containers vs Virtual Machines

Containers and virtual machines have similar resource isolation and allocation benefits, but function differently because containers virtualize the operating system instead of hardware, containers are more portable and efficient

Docker

Docker is the world's leading software containerization platform, there are many other  Docker’s website describes it as “an open-source engine that automates the deployment of any application as a lightweight, portable, self-sufficient container that will run virtually anywhere.”.

• Docker is built on top of LXC, and therefore runs containers, not VMs as VirtualBox for instance 
• Docker containers are made of portable “images”, similar to LXC/VZ templates, but much more powerful (versionning, inheritance …) 
• Docker “images” can easily be created via Dockerfile’s, where are set the base image and the steps to run in order to create your image 
• Docker allows to have run multiple instances of your container without needing to copy the image (base system) files 
• Docker daemon (which manages / runs LXC containers) provides a REST API used by Docker CLI utility … but this REST API can be used by any application 
• Docker runs on virtually all operating systems (Linux, Mac OS, Windows …) and platforms (Google Cloud Platform, Amazon EC2) 

Docker is the world's leading software containerization platform.