Google’s Chrome OS includes a shell environment known as Chrome Shell, or “crosh” for short. Crosh includes several terminal commands that can be used on all Chromebooks, even if developer mode isn’t enabled.

Crosh includes commands for connecting to SSH servers, monitoring resource usage, debugging network problems, tweaking hidden hardware settings, performing hardware tests, and other debugging purposes.

via How-To Geek http://www.howtogeek.com/170648/10-commands-included-in-chrome-oss-hidden-crosh-shell/