A car seat is the chair used in automobiles. Most car seats are made from cheap, but durable materials, made to withstand as much beating as possible. The material for these seats is usually used for the back of the seat, as well as the part where one's posterior goes.

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.

Anti-submarine seat prevents forward movement of the occupant in case of collision. It is a safety feature, important for front seats over rear seats.

A bucket seat is a seat contoured to hold one person, distinct from bench seats which are flat platforms designed to seat multiple people. Bucket seats are standard in fast cars to keep riders in place when making sharp or quick turns.

Some car seat systems are set up with an battery-powered automatic control to adjust how the seat sits in the car.

In suitably equipped cars, seats and mirrors can be adjusted using electric controls. Some vehicles let the driver(s) save the adjustments in memory for later recall, with the push of a button. Most systems allow users to store more than one set of adjustments. This allows multiple drivers to store their comfort settings, or a single driver to store several different occupant positions. Some vehicles associate memorized settings with a specifically numbered, remotely operated key fob, resetting a seat to the position associated with that fob when the vehicle is unlocked (e.g. key fob #1 sets seats to memory position #1, #2 to #2, etc.).

Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License)

For More Information: Child Safety Seat