Stephen King cleverly tells us that the road to hell is thickly paved with adverbs, those modifiers of verbs, adjectives, and other adverbs. They don't always end in -ly, although they often do. (In the previous sentence, always and often are adverbs.)
Adverbs get a bum rap, in my opinion. Like salt in our suppers and passive voice in our writing, they are essential to our language but are easily overdone.