A Box of Matches is a common item used to create and light fireplaces. They are an essential item if you wish to survive for any period of time outside of populated areas because matches, along with a Hatchet and a Hunting Knife, will allow you to kill and eat animals to survive instead of looting cans of food. They are found in residential areas and supermarkets.
This page contains information about the mod version of DayZ. Standalone information is available here.