A car seat is the chair used in automobiles. Most car seats are made from inexpensive but durable material in order to withstand as much use as possible.

The lumbar is the region of the spine between the diaphragm and the pelvis; it supports the most weight and is the most flexible. The adjustable lumbar mechanisms in seats allow the user to change the seat back shape in this region, to make it more comfortable. Some seats are long enough to support full thigh.

A Child Restraint system, also commonly referred to as a child safety seat or a car seat, is a restraint which is secured to the seat of an automobile equipped with safety harnesses or seat belts, to hold a child in the event of a crash.

This kind of seat incorporates specially shaped panels in the forward edge of the seat cushion, reducing the tendency for the occupant to slide beneath the seatbelt in a severe frontal collision. Anti-submarine seating is a safety feature which may be more important for the front seats than the rear seats.

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor. Most definitions of the term specify that automobiles are designed to run primarily on roads, to have seating for one to eight people, to typically have four wheels, and to be constructed principally for the transport of people rather than goods.

The term motorcar has also been used in the context of electrified rail systems to denote a car which functions as a small locomotive but also provides space for passengers and baggage. These locomotive cars were often used on suburban routes by both interurban and intercity railroad systems.

There are approximately 600 million passenger cars worldwide (roughly one car per eleven people). Around the world, there were about 806 million cars and light trucks on the road in 2007; the engines of these burn over a billion cubic meters (260 billion US gallons) of petrol/gasoline and diesel fuel yearly. The numbers are increasing rapidly, especially in China and India.

A seat is place to sit, often referring to the area one sits upon as opposed to other elements like armrests.

A seat is also known as a a bench, a chair, a chaise lounge, chesterfield, a couch, a davenport or a settee.

The following are examples of different kinds of seat:

The word seat comes from Middle English sete and from Old Norse sæti; akin to Old English gesete seat, sittan to sit. The first known use of the word seat is in the 13th century.

Children's author Hugh Lofting referred to a seat in this passage from his novel The Story of Doctor Dolittle; “He came strolling down the gravel-walk, humming a sad song, till he reached a stone seat right under the tree where the parrot and the monkey were hiding.”

Children's author and playwright L. Frank Baum referred to a seat in this passage of his novel Dorothy and the Wizard in Oz; “At once a little girl rose from her seat and walked to the door of the car, carrying a wicker suit-case in one hand and a round bird-cage covered up with newspapers in the other, while a parasol was tucked under her arm.”