What is a strait?

A strait is a naturally formed, narrow, typically navigable waterway that connects two larger bodies of water.

The Palk Strait – connecting two large 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 body of water that is otherwise not navigable, for example because it is too shallow, or because it contains an unnavigable reef or archipelago.

Channels and canals can also be straits when they fit the above description.

Straits are the converse of isthmuses. That is, while a strait lies between two land masses and connects two larger bodies of water, an isthmus lies between two bodies of water and connects two larger land masses.