Overview
A service record is a collection of either electronic or printed material which provides a documentary history of a person's activities and accomplishments while serving as a member of a given organization. Service records are most often associated with the military, but are commonly found in other groups, such as large corporations or for use by employees of a civilian government.
Australian armed forces
Service records for the Australian Army, are available at the National Archives of Australia website. The service records of the Royal Australian Navy and Royal Australian Air Force are also available.
World War I service records provide the dates when the person was "in the field", that is with his unit on active service, if and when they embarked for oversea service, and the names of the units in which the person served. The service record also documents other changes—promotions, transfers, time at base, the date and place of sickness or wounding, and the names of hospital or clearing station where the person was treated.
Canada
Canadian military service records are held by either the Department of National Defence or Library and Archives Canada depending on the age of the file. The Library and Archives Canada is responsible for with acquiring, preserving, and providing accessibility for military service files.
From Wikipedia (CC BY-SA 4.0).