actual article; the item itself
Refers to the physical item being discussed, as opposed to a sample, catalog photo, or description. Common in commercial and auction contexts.
カタログではなく、現品を見てから購入を決めました。
I decided to buy after seeing the actual item, not the catalog.
goods in stock; stock on hand
Used in inventory, retail, and warehouse contexts to refer to items physically present and available.
申し訳ございませんが、その商品は現品限りで売り切れました。
I'm sorry, but that item was the last one in stock and has sold out.
Compound of 現 (gen, 'present, actual') and 品 (hin, 'goods, article'). A straightforward Sino-Japanese word.