Contraceptive literacy is the ability to understand and use reliable information about birth-control methods, effectiveness, side effects, STI protection, and pregnancy prevention.
Typical use describes how well contraception works in everyday life, including missed doses, timing errors, inconsistent use, and other common mistakes.
Method failure means pregnancy occurs even though contraception was used correctly and consistently, distinguishing true failure from mistakes or inconsistent use.
Perfect use means using a contraceptive method correctly and consistently every time, producing effectiveness rates that are usually higher than typical-use rates.