The ship's store was a location aboard Federation starships set aside for items usually not carried in the cargo bays. Such items included apparel, tools, and samples of compounds. On a Galaxy-class starship, ship's stores were located on deck four.
In 2266, aboard the USS Enterprise, Charles Evans gave a gift of perfume to Yeoman Janice Rand. As this perfume wasn't available from ship's stores, she asked Evans where he got it. (TOS: "Charlie X")
In early 2364, aboard the USS Enterprise-D, Lieutenant Natasha Yar went to ship's stores for sexy sleepwear. She was later seen in this sleepwear when seducing Lieutenant Commander Data. (TNG: "The Naked Now")
Later that year, Lore retrieved a macrotool and samples of quadratanium from the Enterprise-D store. With his possessions, Lore knocked out his brother Data with a combination of champagne and quadratanium, and repaired his face with the macrotool. He turned the tool on Data, causing damage to his face. (TNG: "Datalore")
A ship's store was also located on the Promenade of Deep Space 9. This store specialized in selling and repairing starship components. During the Occupation of Bajor, it was the site of a chemist's shop. (DS9: "Necessary Evil")