Google provides hardware that runs its own OS with automatic updates for a fixed period of time after their release. This software policy applies to a range of devices, from Chromebooks to Chromebits, the end-of-life (EOL) of which is known as Auto Update Expiration (or AUE). 140 of these products have had their AUEs amended by 6 months to a year each.
https://www.notebookcheck.net/Google-extends-the-EOL-of-140-different-Chrome-OS-devices-by-up-to-a-year-each.441396.0.html