Using wood or charcoal makes smoke and changes the flavor of the food. Using gas does not. Some people only like one type, and some people like both kinds of grilling.
Very often, grills are used for barbecues.
In the United States, there are cook offs for grilling. The most common meats used are steak, burgers and hot dogs. Grilling food is very common for holidays or celebrations like the 4th of July (United States Independence Day). Most people use a grill more in the summer time when it is hot outside.
It is a very bad idea to touch a hot grill with bare hands.