What are aromatics, what's their chemical composition and how are they manufactured?

What are xylenes?

Xylenes are liquids composed of 8 carbon atoms and 10 hydrogen atoms, configured in a 6 atoms ring shape with a two single atom appendixes. Because there are three possible positions in which the two single atoms can be linked, there are three different xylenes which are often mixed when produced ("Mixed xylenes"). All substances with a basic ring structure are called aromatic hydrocarbons, as they often have a characteristic, "aromatic" smell.