“Conjunction: A word that joins words, phrases, clauses, or sentences. The coordinating conjunctions, and, but, or, not, yet, so, for, join grammatically equivalent elements. Correlative conjunctions (both, and; either, or; neither, nor) join the same kinds of elements.”
Excerpted from: Strunk, William Jr., and E.B. White. The Elements of Style, Fourth Edition. New York: Longman, 2000.