Suggest an editImprove this articleRefine the answer for “What is a base image (base image)?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)A **base image** is the source image from which the build of a Docker image starts. **Key point:** a base image is the foundation on which the rest of the image's layers are "built up" in the Dockerfile.Shown above the full answer for quick recall.Answer (EN)ImageA base image is the source image **from which the build of a Docker image starts**. It sets the starting file system and environment on top of which the layers with the application and dependencies are added. ### **Example to understand this** In a Dockerfile, the line: ```Dockerfile FROM ubuntu:22.04 ``` means that the base will be Ubuntu, and after that we will stack our own layers on top: copy files, install packages, and so on. ### **What a base image can be** 1. **An OS as the foundation** `ubuntu`, `alpine`, `debian` - a minimal system for applications. 2. **A language-based foundation** `python:3.10`, `node:18`, `openjdk:17` - already pre-installed runtimes. 3. **An empty foundation (scratch)** `FROM scratch` - a completely empty base layer for ultra-light images. ### **Why a base image is needed** - it sets the environment and file system for the future container; - it removes the need to configure everything from scratch; - it speeds up the build thanks to ready-made layers. **In short:** a base image is the foundation on which the rest of the image's layers are "built up" in the Dockerfile.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.