This book installs Docker Engine 514 inside the Ubuntu 26.04 225 WSL2 6 distribution and never installs Desktop, for four reasons:
Parity with production. CI runners (GitHub), Jenkins 8,793 agents (Jenkins) and the kind nodes of Kubernetes run on Linux Docker 514 Engines. Learning the same systemctl, daemon.json and /var/lib/docker you will meet on servers removes a layer of translation.
No license question. Engine is Apache 2.0, so every command in this book is free to use at work, whatever the size of your employer.
Less overhead. Desktop adds its own docker-desktop distribution, a Windows GUI and background services beside Ubuntu, on a 4-CPU machine that also runs kind clusters and Jenkins.
Transparency. Everything How Linux Isolates inspected (namespaces, cgroups, overlay mounts, containerd 234,762 ) is directly visible, because the daemon runs in the same distribution as your shell.
The daemons themselves are light. Their resident memory with no containers running:
ps -o rss=,comm= -C dockerd,containerd47776 containerd 72204 dockerd
Together they hold about 117 MB of RSS (figures in KiB). Desktop's real extras, a GUI, one-click Kubernetes 5,150 and automatic updates, are covered here by the CLI, kind (Kubernetes) and apt.