The wok is a versatile round-bottomed cooking vessel originating in the country of China. It is used especially in East and Southeast Asia.
It is most often used for stir frying, but can also be used many other ways, such as in steaming, deep frying, braising, stewing, or making soup. It is commonly, almost exclusively, cooked with a long handle "chahn" (spatula) and/or a long handle "hauk" (ladle). The reason why these utensils are longer than normal is to allow the cook to stir and manipulate the food without burning one's hand(s).
The best place to buy authentic woks are Chinese or ethnic food wholesalers such as at Seewoo.
To ensure the wok does not stick, it needs to be properly "seasoned" (nothing to do with salt and pepper). A good article on wok seasoning can be found here