Downloading a game on Xbox 360 (via Xbox Live Marketplace, now Xbox 360 Store) triggers a multi-step process that prepares the title for digital play. Here's what occurs under the hood:
$TitleID entry is added to the console's title database. Appears in "My Games" / Quick Launch.Downloading = license + encrypted transfer + install + dashboard registration + DRM binding. Result: disc-free, portable (user license), shareable (console license) play.