A lagoon is connected to the sea, seawater, an area that is isolated at least some of the time from the sea. Usually the other side of a sandbank, or reef. A lake is generally not small. A pond is generally not large.

I remember learning at school that the difference between a pond and a lake is that a lake is fed by rivers or streams but a pond is not. This seems to be the geographer's definition. It is the kind of thing native speakers might argue about though!

All of these words refer to an area of water. A lagoon is an area of sea water separated from the sea by either reef or sand. A lake is a large area of water surrounded by land and not connected to the sea except by rivers or streams. A pond is an area of water smaller than a lake and can be artificially created. A region that contains a certain amount of water can be called a wetland. A wetland consists of marshes or swamps; in other words it is saturated land. The St Lucia Wetlands in South Africa boast a rich wildlife. Hope this assists you. Teacher Mark

Nanren's answer sums up the different bodies of water succinctly. However, i would just add that a general term for a region with a lot of standing water would be "Wetlands" Possibly the area might be termed marshlands or swamps. A good example of this would be the EVERGLADES in Florida Or The Norfolk Broads in England, where i come from. This area in Norfolk is also known as "The Fens"

Lake