What is Docker and Docker Containers? What are they? Explain like I’m 5

3 min readJun 11, 2022

Allow me to tell you a story that takes place many years ago. Long ago, before there were such things as containers, large corporations like Walmart, Target, and Chase Bank, to name a few, were required to take precautions to ensure that their businesses never went offline because they were dependent on technology. As a consequence of this, they would buy servers, then buy additional servers, and then the process would continue, which would ultimately lead to an overallocation of resources. At the time, businesses believed that doing business in this manner would be more efficient because it would allow them to make better use of the costly resources that they had acquired by allowing them to run additional applications independently within the same bare metal server environment. This was a really neat experience.

Fast forward to modern-day containerization, and we have Docker, a fantastic technology. Docker is great because, for one thing, it’s extremely lightweight, and we won’t have the issues of having these crazy to configure virtual machine images that are difficult to set up and difficult to deploy. Docker works off images, and you can create containers out of these images, which makes it extremely lightweight. It boots up in seconds and is ready to use right away on your host machine.

One of the most significant advantages of Docker over something like a virtual machine is the absence of a hypervisor, basically, it doesn’t have a separate kernel, it still uses the same resources as the host OS, and it exploits namespaces and control groups too tightly.