baby bed vs cot

baby bed and cot both are nouns.

Word	Noun	Adjective	Verb	Adverb
baby bed	Yes	No	No	No
cot	Yes	No	No	No

As nouns, cot is a hyponym of baby bed; that is, cot is a word with a more specific, narrower meaning than baby bed:

baby bed: a small bed for babies; enclosed by sides to prevent the baby from falling
cot: baby bed with high sides made of slats

Other hyponyms of baby bed include bassinet, carrycot, cradle, crib.

baby bed (noun)	cot (noun)
a small bed for babies; enclosed by sides to prevent the baby from falling	a small bed that folds up for storage or transport
	baby bed with high sides made of slats
	a sheath worn to protect a finger