Criminal law deals with actions/deeds/behavior that is or are often construed as an offense against the overall public, society, or the state—even if the immediate victim is Public Person. Examples are murder, assault, theft, and drunken driving. In such cases either FIR is registered or GD/DD entry/ Challan is made. In criminal cases, Police/Forces/Agencies are directly involved in getting the culprit punished by the court of law.
In private cases which are also called Complaint Cases like cheque bouncing and other criminal cases, police and forces are not involved but the Private/Individual has to lead his own case and has to prove his case against the accused and the court decides the matter after considering the evidence and material available on record and thereby punishes or acquits the accused accordingly.