criminal law protects society
Civil law regulates actions between individuals or groups.
Cases that included in criminal laws usually consist of cases that perceived as harmful, threatening, and dangerous for other people in society. (for example: murder, arson, terror attacks, etc).
Cases that included in civil law on the other hand, usually consist of conflicts of interests between different individuals in society. (for example: Conflict about business contract, conflict about renters that haven't pay their responsibilities , etc)