A warrant-case is defined to mean a case relating to an offence punishable with death, imprisonment for life or imprisonment for a term exceeding two years. A summons-case means a case relating to an offence, not being a warrant-case.
The code classifies all offences into cognizable and non-cognizable, and the trial procedure into summons-cases and warrant-cases. This division is based on the nature and measure of punishment attached to the offence.
It is to be noted that this distinction is distinct and different from the question whether a summons or a warrant would issue in the first instance and whether an offence is cognizable or not.