Whoever commits culpable homicide not amounting to murder, shall be punished with [imprisonment for life], or imprisonment of either description for a term which may extend to ten years, and shall also be liable to fine, if the act by which the death is caused is done with the intention of causing death, or of causing such bodily injury as is likely to cause death;
or with imprisonment of either description for a term which may extend to ten years, or with fine, or with both, if the act is done with the knowledge that it is likely to cause death, but without any intention to cause death, or to cause such bodily injury as is likely to cause death.
Meaning: Section 304 of the IPC talks about the punishment for culpable homicide not amounting to murder, which happens when a person causes the death of another, but the circumstances reduce the offence from murder to culpable homicide, typically due to the lack of intent and due to some legal exceptions, such as self-defense or sudden provocation.
Part I: With Intention
When the act is accompanied by the intention to cause death, or to cause such bodily injury which is likely to cause death, the law takes a more serious view of the matter, in which case the punishment may be: life imprisonment, or imprisonment which may be either rigorous or simple, for up to 10 years along with fine.
Example: If A hits B on the head with a heavy rod in a sudden quarrel, knowing that it was likely to cause death, and B dies, A may be punished in accordance with Part I, if exceptions to murder apply.
Part II: With knowledge and without intention
Where the crime is committed with knowledge but without any intention of causing death or such bodily injury, the penalty is less severe. The court may impose only imprisonment either rigorous or simple for a maximum of 10 years, or a fine, or both.
Example: C while driving recklessly, speeds through a market which is filled with shoppers, killing D upon impact. C knew he was driving to a degree of danger but had no intention to kill.
Difference from murder
The primary difference is in the mental state of the accused. Murder requires proof of higher intent, while Section 304 would cover cases where intention was absent or attention had been diminished due to certain circumstances.