A cargo boat, also known as a freighter, is a vessel designed to transport goods in bulk. Synonyms for this type of maritime transport include container ship, bulk carrier, tanker, barge or flat-bottomed boat, and livestock carrier. Container ships are specifically designed to transport huge quantities of standardized shipping containers while bulk carriers are designed to transport dry goods such as coal and grains. Tankers are used to transport liquid cargo such as oil and chemicals while barge or flat-bottomed boats are used to transport cargo within rivers and canals. Livestock carriers, as the name suggests are specifically designed to transport livestock like cattle, pigs, and sheep.