If you already have a criminal conviction on your record, this can increase the penalties that you face for a second or subsequent conviction. You may also be facing multiple charges for more than one alleged crime at the same time. Prosecutors often do this in an attempt to make sure at least one charge sticks.
If you are found guilty of more than one charge against you, this will affect the sentence that the judge orders. While a judge must avoid a “double punishment” for the same type of misconduct, a judge can order two sentences to be carried out concurrently, meaning simultaneously, or carried out consecutively, meaning one after another.