Installing Docker and Running Your First Command

Now we install Docker on your machine and confirm it really works — in two short commands. On Mac and Windows you install an app called Docker Desktop; on Linux you install Docker Engine. After installing, we run one command that proves, in black and white, that Docker is ready to work on your machi

It is like installing a new app on your phone and then opening it once to confirm it works. Here the 'first open' is one small command.

Docker Desktop: An app for Mac and Windows that installs everything needed to run Docker, including the engine itself. You open it once and it runs in the background.
Docker Engine: The program that actually builds and runs containers. On Linux you install it directly; on Mac/Windows it comes inside Docker Desktop.
daemon: The part of Docker that runs in the background and waits for commands. If it is not running, docker commands fail with 'cannot connect to the Docker daemon' — the fix is to start Docker Desktop.