In the classical sense, smog equals smoke plus fog, but for the people who live in sun-drenched basins, such as Los Angeles, the equation is a little more complicated. Classical smog is primarily the product of coal-fueled fires from factories and is also known as industrial smog. The smog common in Los Angeles comes from automobile and other fossil-fuel emissions; since the energy of the Sun makes it noxious, it's known as photochemical smog.
An emperor (through Old French empereor from Latin: 'imperator') is a monarch, usually the sovereign ruler of an empire or another type of imperial realm. Empress, the female equivalent, may indicate an emperor's wife (empress consort), mother (empress dowager), or a woman who rules in her own right (empress regnant). Emperors are generally recognized to be of a higher honour and rank than kings.
A Roman emperor was the man who ruled over the empire. The first Emperor ruled Rome after years of fighting between rival leaders. His name was Octavian. He took a new name, Augustus, when he became Emperor in 27 BC. Augustus brought peace after years of fighting. Not all the emperors were good and wise.