In Docker, an image is a package that contains all the necessary files and settings for running an application. It includes everything needed to launch a separate container, including code, runtime environment, libraries, dependencies, and configuration files.

Images can be built using a Dockerfile, which describes the steps to create the image, including the base image, environment setup, and installation of necessary dependencies.

Each container is launched from an image. Containers are instances of images and can be created, started, stopped, removed, and moved to other systems.

Creating a container from an image is similar to the process of cooking a dish according to a culinary recipe. You use the ingredients (software components) specified in the recipe (Dockerfile) and follow the instructions to obtain the final product — a container.