Sure, you can use clamshell mode.
Plug in an external display and a USB keyboard/mouse.
While your system is running, close the lid. It will sleep normally.
Press a key on your external keyboard.
Your MacBook Pro will now wake up, displaying video on the external display, while the lid remains closed, and the internal display will remain off.
Lid closed, but awake.... You wouldn't want the lid closed while the display remains powered up risking overheating. Clamshell mode is the only safe way to do that.
Does that help answer your question?