“Lighting is really common sense and personal observation. This is applied to a few rules of photography which cannot be broken and to others which I tend to bend a little.”—Paul Beeson
A monolight or monobloc to our European friends is a self-contained studio flash that is typically, but not always, powered by an AC power source and allows for different light modification devices, including reflectors, light banks, or umbrellas. The key phrase in that last sentence is self-contained. To my way of thinking the biggest advantage monolights possess is just that—if you’re shooting on location or for that matter anywhere and the power pack in a pack and head system stops working, so do you. If you have a couple of monolights and one of them fails, you can still shoot.