Definition from Nolo’s Plain-English Law Dictionary
When a criminal defendant is convicted of two or more crimes, a judge sentences the defendant to a certain period of time for each crime. Sentences that may all be served at the same time, with the longest period controlling, are concurrent sentences. Judges may sentence concurrently out of compassion, plea bargaining, or the fact that the several crimes are interrelated. When the sentences run one after the other, they are consecutive sentences.