On the Food network they boil potatoes, but they poach carrots. They poach turkey, but they boil eggs. They sauté’ onions, but they fry eggs in the same pan. Likewise, they fry hash browns, but they sauté’ onions in the same pan before adding the potatoes.
I can go on for days.
There’s a few different things here that make clarity difficult. One is the precise definition of various techniques, for example:poaching water is not bubbling, simmering water is gentle bubbles, boiling water is bubbling heavily(some say “full rolling boil”, which is what boiling always is. Second is simply the name of the cooking vessel/equipment, griddle vs grill vs broiler, which is sometimes the same term used to describe the technique applied. You can grill a steak, but you wouldn’t say you ovened a roast. Last is that many terms are misused so much that it’s just become common parlance. Technically a grill is a device with grates and a radiant device that cooks food through a combination of conduction and radiation, usually powered by propane or natural gas. A BBQ is a similar object powered by wood, but it’s common for an outdoor grill to be referred to as a BBQ, though when used with the lid down is a little different than an open restaurant style grill since it acts a bit like an oven too.