Simplify the following text for a Grade 14 native English-speaking person.
Original: 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 .
Simplified: It most commonly means a channel of water that lies between two land masses , but it may also mean a navigable channel through a body of water that is not navigable , for example because it is too shallow , or because it contains an unnavigable reef or archipelago .