It is propelled by a double-bladed paddle in the hands of a sitting paddler. The kayak was used by the native Ainu, Aleut and Eskimo hunters in sub-Arctic regions of northeastern Asia, North America and Greenland. Modern kayaks come in a wide variety of designs and materials for specialized purposes. Kayaks are in some parts of the world referred to as canoes.The term "kayak" is increasingly applied to many craft that diverge substantially from traditional kayaks.

--Inflatable kayaks
An special type of kayak is the inflatable kayak, also known as the "ducky". Inflatable kayaks usually can be transported by hand using a carry bag. They are made of hypalon (a kind of neoprene), PVC, or polyurethane coated cloth. They can be inflated with foot, hand or electric pumps. They generally use low pressure air, almost always below 3 psi.
Until recently, inflatable kayaks have been non-rigid boats, essentially pointed rafts, and best suited for use on rivers and calm water. However, recently some manufacturers have combined folding kayak design principles (notably the use of an internal frame) with "Sit-on-top kayak" (see above) overall design using multiple inflatable sections to produce a seaworthy inflatable sea kayak.
Besides being portable, inflatable kayaks generally are stable with a small turning radius and are easy to master, but they take more effort to paddle and are slower than traditional kayaks.

--Pedal kayaks
A special type of kayak using pedals allows the kayaker to propel the vessel with a propeller or underwater "flippers" attached to pedals in the cockpit, rather than with a paddle. This allows the kayaker to keep his or her hands free for fishing or other activities, but introduces a somewhat delicate mechanical component into the boat and eliminates the paddle as a tool for capsize-prevention and self-rescue.

--Multi-hull and outrigger kayaks
Traditional multi-hull vessels such as catamarans and trimarans benefit from increased lateral stability without sacrificing their speed but these advantages cannot be successfully applied in all multihull kayak models Outrigger kayaks, are equipped with either a single or a pair of usually smaller hulls (outriggers) attached to the main hull to provide additional stability, especially for fishing, touring and kayak sailing. Twin hull sit-on-top and sit-in kayaks have been on the market for many years. The inflatable models are popular in whitewater and fishing applications and the Polyethylene models in fishing and recreation.