The following is a summary of startup options available in virtual box start up .

Start with GUI

This launches the VM in a standard window, complete with 3D graphics support—provided 3D acceleration is enabled, Guest Additions are installed, and the OS supports it.

Detachable vs. Headless

These modes are essentially the same: neither provides 3D acceleration, even if it’s enabled in the VM settings.

Start without GUI (Headless)

Think of this as “monitorless.” The VM’s graphics system runs, but no window appears—like a monitor turned off and tucked away. The guest OS still renders the GUI, which you can access remotely via native protocols or VirtualBox RDP/VNC. To display the window, click Show in VirtualBox Manager, which switches to Detachable mode. To hide it again, use Machine → Detach GUI. You can toggle between visible and hidden as needed.

Start with Detachable GUI

This is simply a headless VM with its monitor visible in a window. You can show or hide the window at will, using the same toggle options as in headless mode.