The 105 species of Gulls, Terns & Skimmers (Laridae) have traditionally beed split into three different families, but recent molecular findings have shown that they are better treated as one family.

The relationships are not fully resolved but they can be devided into three groups:
-Basal Larids, including skimmers, noddys and white terns
-Core terns
-Gulls

The skimmers are the only birds with distinctive uneven bills with the lower mandible longer than the upper. This remarkable adaptation allows them to fish in a unique way, flying low and fast over streams. Their lower mandible skims or slices over the water's surface ready to snap shut any small fish unable to dart clear. They are the only birds known to have slit-shaped pupils. Their bills fall within their field of binocular vision and enable them to carefully position their bill and capture prey. They are one of the most agile birds in air that gather in large flocks, loafing on river and coastal sand banks.

Terns are in general medium to large birds, typically with grey or white plumage, often with black markings on the head. They have longish bills and webbed feet. They are lighter bodied and more streamlined than gulls, and look elegant in flight with long tails and long narrow wings. Terns in the genus Sterna have deeply forked tails, those in Chlidonias and Larosterna shallowly forked tails, while the noddies have unusual 'notched wedge' shaped tails, the longest tail feathers being the middle-outer, not the central nor the outermost. Most terns hunt fish by diving, often hovering first, but the marsh terns pick insects of the surface of fresh water. Terns only glide infrequently; a few species, notably Sooty Tern, will soar high above the sea. Many terns breeding in temperate zones are long-distance migrants, and the Arctic Tern probably sees more daylight than any other creature, since it migrates from its northern breeding grounds to Antarctic waters.

Gulls are typically medium to large birds, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls, stout, longish bills, and webbed feet. Most gulls, particularly Larus species, are ground nesting carnivores, which will take live food or scavenge opportunistically. Live food often includes crabs and small fish. Apart from the kittiwakes, gulls are typically coastal or inland species, rarely venturing far out to sea. Gulls — the larger species in particular — are resourceful, inquisitive and intelligent birds, demonstrating complex methods of communication and a highly developed social structure. For example, many gull colonies display mobbing behaviour, attacking and harassing would-be predators and other intruders. Certain species have exhibited tool use behaviour, using pieces of bread as bait with which to catch goldfish, for example. Many species of gull have learned to coexist successfully with humans and have thrived in human habitats. Others rely on kleptoparasitism to get their food.