> ## Documentation Index > Fetch the complete documentation index at: https://docs.fly.io/llms.txt > Use this file to discover all available pages before exploring further. # Fly Machines Illustration by Annie Ruygt of a server with legs and arms, walking with a red bird hand-in-hand Fly Machines are fast-launching VMs; they can be started and stopped at subsecond speeds. We give you control of your Machine count and each Machine's lifecycle, resources, and region placement with a simple REST API or flyctl commands. * [**Introduction to Fly Machines**:](/machines/overview) Learn whether you need low-level Machine control. Find out more about the lifecycle of Fly Machines and about scaling and placement. * [**Machines API:**](/machines/api) A simple and fast REST API for full control over our fast-launching Machines. * **[Run a New Machine](/machines/flyctl/fly-machine-run) or [Update a Machine](/machines/flyctl/fly-machine-update) with flyctl:** Configure, build, and start new Machines with a single command or update some or all of a Machine's configuration. On the other hand, try [Fly Launch](/reference/fly-launch) if you prefer easy app-wide configuration and containerized deployment for your app.