A boat is a watercraft of any size designed to float or plane, to provide passage across water. Usually this water will be inland (lakes) or in protected coastal areas. However, boats such as the whaleboat were designed to be operated from a ship in an offshore environment. In naval terms, a boat is a vessel small enough to be carried aboard another vessel (a ship). Another less restrictive definition is a vessel that can be lifted out of the water. Strictly speaking and uniquely a submarine is a boat as defined by the Royal Navy^{[citation needed]}. Some boats too large for the naval definition include the Great Lakes freighter, riverboat, narrowboat and ferryboat. The term armed boat, used primarily by English speaking naval forces, referred to any boat carrying either a cannon or armed occupants, such as marines^{[citation needed]}.

Boats have served as short-distance transportation since early times. Circumstantial evidence, such as the early settlement of Australia over 40,000 years ago, and findings in Crete dated 130,000 years ago, suggests that boats have been used since ancient times. The earliest boats have been predicted to be logboats. The oldest boats to be found by archaeological excavation are logboats from around 7,000–10,000 years ago. The oldest recovered boat in the world is the Pesse canoe; it is a dugout or hollowed tree trunk from a Pinus sylvestris. It was constructed somewhere between 8200 and 7600 B.C. This canoe is exhibited in the Drents Museum in Assen, Netherlands; other very old dugout boats have been recovered. A 7,000 year-old seagoing boat made from reeds and tar has been found in Kuwait.

The phrases Fresh off the boat (FOB), Off the boat (OTB), Freshy, or just simply Boat; are terminologies used to describe immigrants that have arrived from a foreign nation and have not yet assimilated into the host nation's culture, language, and behaviour. "Fresh off the Boeing" is sometimes used in the United States as a variation, especially amongst south and south-east Asian immigrants. Within some ethnic Asian circles in the United States, the phrase is considered politically incorrect and derogatory. It can also be used to describe the stereotypical behavior of new immigrants as, for example, their poor driving skills, that they are educated yet working low-skilled or unskilled jobs, and their use of broken English. The term originates in the early days of immigration, when people mostly migrated to other countries by ship.

In the sociology of ethnicity, this term can be seen as an indicator of a nature of diasporic communities, or communities that have left their country of origin and migrated, usually permanently, to another country. The term has also been adapted by immigrants themselves or others in their community who see the differentiation as a source of pride, where they have retained their culture and have not lost it to assimilation. In fact, instead of taking this harm-intended phrase as an insult, many Korean, Japanese, Pakistani, Sri Lankan, Indian, and Chinese people (especially their American-born children) use this term to describe their cultural Asian habits and fashion sense, for example "fobby clothing", "fobby glasses" and "fobby accent."