What is a Docker image?

A Docker image is an independent, executable package that is used for the construction of Docker containers and contains everything needed to execute a piece of software, including its code, runtime, system tools, libraries, and settings. Docker images are generated using a Dockerfile, which is a script that describes the image's dependencies and parameters.

Docker images are saved in registries like Docker Hub, where they may be shared and downloaded by others. This enables developers to simply distribute and deploy their apps and services across several environments without worrying about underlying infrastructure or dependencies.