Ranger is a position within the Night's Watch, the most prestigious of the three groups. They are tasked with patrolling the lands Beyond the Wall, particularly the Haunted Forest, to scout the movements of the Free Folk and prevent their attacks against the Wall. Recruits of the Night's Watch are sorted into Rangers, Builders, and Stewards depending on their personal specialities and strengths. Recruits who show martial skill are usually assigned as Rangers (although Builders and Stewards do have some martial training).
The Rangers collectively report to the First Ranger, who in turn reports to the Lord Commander of the Night's Watch.