Answer:
Homicide and murder are both legal terms for the unlawful killing of another person.
There are different degrees of unlawful killing. The worst case is premeditated murder where the act has been thought about and planned in advance.
A less severe form of punishment or sentence may be applied where someone may have been killed by accident though someone is still directly responsible.
These are completely different to the lawful killing carried out by officers of the law and servicemen. In certain circumstances it is also lawful for a civilian to kill another person.