A strait is a narrow, navigable channel of water that connects two larger navigable bodies of water. It most commonly refers to a channel of water that lies between two land masses, but it may also refer to a navigable channel through a body of water that is otherwise not navigable, for example because it is too shallow, or because it contains an unnavigable reef or archipelago. The terms strait, channel, passage, sound, and firth can be synonymous and interchangeable, although each is sometimes differentiated with varying senses. Many straits are economically important. Straits can lie on important shipping routes, and wars have been fought for control of these straits. Numerous artificial channels, called canals, have been constructed to connect two bodies of water over land.
Although rivers and canals often form a bridge between two large lakes or a lake and a sea, and these seem to suit the formal definition of straits, they are not usually referred to as straits. Straits are typically much larger, wider structures.
Straits are the duals of isthmi. That is, while straits lie between two land masses and connect two larger bodies of water, isthmi lie between two bodies of water and connect two larger land masses.
A strait is similar to an inlet although inlets typically pass through island land masses usually from a large body of water such as an ocean to a much smaller body such as a bay while straits pass through much larger land masses and connect much larger bodies of water such as seas and oceans.
Well-known straits in the world include: