A merchant vessel is a type of ship or boat that is primarily used for commercial purposes such as transporting cargo, passengers or other goods. There are various synonyms for the term "merchant vessel" that can be used interchangeably. Examples of these synonyms include cargo ship, freighter, tanker, bulk carrier and container ship. A cargo ship is primarily used for carrying large quantities of goods while a freighter can transport larger and bulkier cargoes. Tankers are specialized vessels used for transporting crude oil and petroleum products while bulk carriers are designed to carry dry goods such as grains and coal. Container ships are vessels designed to transport cargo in standardized shipping containers.