The elementary stages of any subject (usually plural)(noun)
WordNet. Princeton University. 2010.
Use "abc's" in a sentence
"You too can make a change in your schools - it can be as easy as abc's and 123's."
"Did she recite her abc's and get all the way thru it?"
"Her "modern design deck" series of prints covers the abc's of modern furniture design and comes in a limited edition of 250, each print signed, numbered, and dated."