"BED" and "RED" are both acronyms standing for Black Eyed Demon and Red Eyed Demon, respectively. A Black Eyed Demon is a soldier demon while a Red Eyed Demon is a deal-making demon.
|EMF Detector: |
Sam and Dean often use EMF Detectors while hunting the demons. An EMF Detector is a devise that measure electromagnetic fields -- a region of space where electric charges experience a physical influence, often attributed to supernatural beings.
In various episodes, Sam and Dean often use the word "spooks" in place of ghosts or spirits.
Dean says whenever he's figured out, or found something out.
The acronym "YED" stands for Yellow Eyed Demon. Dean first used the term in "Croatoan" and was used frequently in subsequent episodes.
The YED is the demon that killed Mary Winchester, John's wife, Dean and Sam's mother. It was also responsible for the death of Sam's girlfriend Jessica Moore