What is meant by parties to a crime?

Every crime is an event with a cast: who held the knife, who drove, who planned, who supplied, who sheltered. The law of parties assigns criminal liability across the cast. The analytical question: does criminal law punish only the hand that acts, or also the minds and hands that contributed? Every system answers broadly — liability extends — but by different techniques: The common law's historical device: principal in the first degree (the actor), principal in the second degree (the aider present at the crime — "standing by, ready to help"), accessory before the fact (advance assistance), accessory after the fact (harbouring with knowledge) — a taxonomy built on physical position and timing; The Subcontinental-Nepali technique: the general-part categories of principal offender and abettor (the Muluki Ain tradition, continued by the 2074 Code), with abetment's own structure (instigation, aid, conspiracy — Unit 5); The civil-law device: the unitary author/participant grades (perpetration and participation); The American modern approach: complicity statutes treating aiders as principals, plus the Pinkerton conspiracy doctrine.