Clawed lobsters comprise a family (Nephropidae) of large marine crustaceans. They are not to be confused with spiny lobsters, which have no claws (chelae), and are not closely related. The closest relatives of clawed lobsters are the reef lobster Enoplometopus and the three families of freshwater crayfish.

Smaller varieties are sometimes called "lobsterettes". Lobsters are invertebrates, and have a tough exoskeleton, which protects them. Like all arthropods, lobsters must molt in order to grow, leaving them vulnerable during this time. Lobsters are considered a food delicacy around the world. In Europe, they are extremely expensive; in some parts of North America, much less so.

Lobsters live on rocky, sandy, or muddy bottoms from the shoreline to beyond the edge of the continental shelf. They generally live singly in crevices or in burrows under rocks.

Lobsters are basic scavengers, feeding on mollusks and decaying animal matter. Lobsters are not entirely scavengers, however; they also eat live fish, dig for clams, and feed on algae and eel grass. An average adult lobster is about nine inches (230 mm) long and weighs 1.5 to 2 pounds (700 to 900 g). Lobsters grow throughout their lives, though, and are long-lived. They can thus reach impressive sizes. According to the Guinness World records, the largest lobster was caught in Nova Scotia, Canada and weighed 20.14 kg (44.4 lb).

The environmental conditions of the lobsters can vary from ocean to ocean, but the lobster's temperature environment does not fluctuate much since their home is large mass of water, the ocean.

Like all arthropods, lobsters are bilaterally symmetrical. The anatomy of the lobster includes the cephalothorax which is the head fused with the thorax, both of which are covered by the carapace, and the abdomen. The lobster's head consists of antennae, antennules, mandibles, the first and second maxillae, and the first, second, and third maxillipeds. Because a lobster lives in a murky environment at the bottom of the ocean, its vision is poor and it mostly uses its antennae as sensors. The abdomen of the lobster includes swimmerets and its tail which is composed of uropods and the telson.

Most lobster comes from the Northeast coast of North America with the Canadian Maritimes and the state of Maine being the largest producers. They are caught using lobster traps. These devices made of net and wood are baited and lowered to the sea floor. They allow a lobster to enter, but make it impossible for them to turn around and exit. This allows the creatures to be captured alive. The traps have a buoy floating on the surface and lobster fishermen check their traps daily.

Lobster is normally cooked by dumping them while live in a pot of boiling water. Lobster is best eaten fresh, and they are normally purchased and cooked live. Restaurants that serve lobster keep a tank of the live creatures, often allowing patrons to pick their own. Lobsters are often eaten plain or with butter, lobster can be cut up and used in a wide array of dishes. The shell of the lobster makes eating them a slow process, requiring a number of implements. The majority of the meat is in the tail and the two front claws, but smaller quantities can be found in the legs and torso.

The eating of lobster changed dramatically over the twentieth century. At the beginning they were unknown in most of the world and not considered sellable. Fishermen caught them occasionally and they were only consumed by the poorer sections of the population. In the Canadian Maritimes eating lobster was considered a mark of poverty. Outside of the rural outports lobster was sold canned, losing much of its flavour. The reputation of lobster changed with the development of the modern transportation industry that allowed live lobsters to be shipped from the outports to the large urban centres. Fresh lobster quickly became a luxury good and a tourist attraction for the Maritimes and Maine and an export to Europe and Japan where it is especially expensive.

In Canada, Shediac, New Brunswick promotes itself as the "Lobster Capital of the World".

Types include:

• Atlantic deep-sea lobster (Acanthacaris caeca)
• Prickly deep-sea lobster (Acanthacaris tenuimana)
• Red lobster (Eunephrops bairdii)
• Sculptured lobster (Eunephrops cadenasi)
• Banded lobster (Eunephrops manningi)
• American lobster (Homarus americanus)
• Cape lobster (Homarus capensis)
• European lobster (Homarus gammarus)
• Andaman lobster (Metanephrops andamanicus)
• Arafura lobster (Metanephrops arafurensis)
• Armored lobster (Metanephrops armatus)
• Northwest lobster (Metanephrops australensis)
• Caribbean lobsterette (Metanephrops binghami)
• New Zealand lobster (Metanephrops challengeri)
• Formosa lobster (Metanephrops formosanus)
• Japanese lobster (Metanephrops japonicus)
• African lobster (Metanephrops mozambicus)
• Neptune lobster (Metanephrops neptunus)
• Urugavian lobster (Metanephrops rubellus)
• Sculpted lobster (Metanephrops sagamiensis)
• Siboga lobster (Metanephrops sibogae)
• China lobster (Metanephrops sinensis)
• Red-banded lobster (Metanephrops thomsoni)
• Velvet lobster (Metanephrops velutinus)
• Bight lobster (Metanephrpos boschmai)
• Mitten lobsterette (Nephropides caribaeus)
• Norway lobster (Nephrops norvegicus)
• Spinetail lobsterette (Nephropsis acanthura)
• Florida lobsterette (Nephropsis aculeata)
• Prickly lobsterette (Nephropsis agassizii)
• Scarlet lobsterette (Nephropsis atlantica)
• Ridge-back lobsterette (Nephropsis carpenteri)
• Gladiator lobsterette (Nephropsis ensirostris)
• Saya de Malha lobsterette (Nephropsis malhaensis)
• Ruby lobsterette (Nephropsis neglecta)
• Pacific lobsterette (Nephropsis occidentalis)
• Rosy (or Two-toned) lobsterette (Nephropsis rosea)
• Indian Ocean lobsterette (Nephropsis stewarti)
• Red and White lobsterette (Nephropsis suhmi)
• Grooved lobsterette (Nephropsis sulcata)
• Bellator lobster (Thymopides grobovi)
• Patagonian lobsterette (Thymops birsteini)
• Nilenta lobsterette (Thymopsis nilenta)

See also spiny lobster.