Install and verify Docker

Install Docker Desktop on macOS or Windows, or Docker Engine from Docker’s repository on Linux. Use the current official instructions for your operating system.

The docker command is a client. Most commands ask a long-running Docker engine to create images, containers, networks, and volumes. A working client with an unreachable engine is not a working installation.

docker version
docker info
docker run --rm hello-world

These commands test different parts of the path. docker version proves that the client can negotiate with the server. docker info asks the selected engine for its configuration. hello-world also exercises image lookup, download, container creation, process startup, logs, and cleanup.

If the client exists but the server section is missing, check docker context show before reinstalling anything. A context points the client at a particular engine. On Docker Desktop, also verify that the application is running. This distinction prevents a daemon connection problem from being mistaken for a broken CLI.

Run all three commands. Read the client and server sections of docker version instead of checking only that the executable exists.