What is it?
A container is an isolated environment to run applications, containing everything the code needs in order to run, down to the operating system, totally isolated from any external factors or other containers.
One might think a container is the same as a virtual machine. They are indeed, very similar, but containers are incredibly faster. Instead of virtualizing hardware, as virtual machines does, a container virtualizes only the software. If multiple containers are needed, they can run on a single Kernel. In other words, containers donāt replicate the hardware, but all the operating system and dependencies needed.
This creates a standardized unit that can run on any system with a container runtime engine, like Docker.
Creating containers
Containers are most commonly associated with Docker, which is the most popular containerization tool. However, thereāre a lot of open-source alternatives, like podman.