Docker Image

A Docker image, or container image, is a standalone, executable file used to create a container. This container image contains all the libraries, dependencies, and files that the container needs to run. A Docker image is shareable and portable, so you can deploy the same image in multiple locations at once—much like a software binary file. 

You can store images in registries to keep track of complex software architectures, projects, business segments, and user group access. For instance, the public Docker Hub registry contains images such as operating systems, programming language frameworks, databases, and code editors.