galley vs ship's galley

galley and ship's galley both are nouns.

Word	Noun	Adjective	Verb	Adverb
galley	Yes	No	No	No
ship's galley	Yes	No	No	No

As nouns, galley and ship's galley are synonyms defined as:

Other synonyms of galley include caboose, cookhouse.

galley (noun)	ship's galley (noun)
the area for food preparation on a ship	the area for food preparation on a ship
the kitchen area for food preparation on an airliner
(classical antiquity) a crescent-shaped seagoing vessel propelled by oars
a large medieval vessel with a single deck propelled by sails and oars with guns at stern and prow; a complement of 1,000 men; used mainly in the Mediterranean for war and trading