An infraction is usually the breaking of a law, rule, or agreement. So a nation charged with an infraction of an international treaty will usually have to pay a penalty. In Federal law, an infraction is even smaller than a misdemeanor, and the only penalty is a fine. Most of us occasionally commit infractions of parking laws and get ticketed; speeding tickets are usually for infractions as well, though they go on a permanent record and can end up costing you money for years to come. The closely related word infringement generally refers to a violation of a right or privilege; use of another's writings without permission, for example, may be an infringement of the copyright.