BlueOS is a headless Raspberry Pi image (there is no visual interface over HDMI or VNC). It’s intended for use on vehicles that generally don’t have a screen to interact with directly, so instead its visual configuration interface is available over IP (internet protocol) via a web browser on a separate computer (or phone/tablet) with an ethernet (or shared wifi) connection to the Raspberry Pi running BlueOS.
Some functionalities are only available when the computer that’s interfacing with BlueOS is configured with a static IP address of 192.168.2.1.