Um, no.
> Is "ChromeBook" an operating system, a system architecture, or what?
It's a brand name for laptop form-factor devices running the ChromeOS operating system.
> It uses the App store from my Android phone, does that mean my phone apps will work on this thing?
It supports Android Apps from the Google Play Store, so, yes, apps that run on other Android devices, including phones, will generally work on it
Um, no.
> Is "ChromeBook" an operating system, a system architecture, or what?
It's a brand name for laptop form-factor devices running the ChromeOS operating system.
> It uses the App store from my Android phone, does that mean my phone apps will work on this thing?
It supports Android Apps from the Google Play Store, so, yes, apps that run on other Android devices, including phones, will generally work on it