A Navigation point, also referred as nav point and waypoint, is an indicator feature that shows the direction of the objective or destination. Nav points are one of the most important tools in Halo and in almost any game. While most of the time it's possible to follow the flow of enemies and continue going straight, this is not always true and the nav point is key.
Navigation points commonly appear in a player's screen in objective multiplayer games, such as Capture the Flag, Oddball and VIP. Navpoints also appear in co-op mode, indicating the position of teammates. They are present in Campaign, and are placed if the player must reach a destination (in some cases, a vehicle, such as Sergeant Johnson's Warthog from Halo 3), and also if they player does not know where to go.
In Halo: Combat Evolved, the waypoints are colored orange in single player, and red or blue in multiplayer, depending on the objective. In Halo 2 and Halo 3, they are blue when playing as John-117, and purple when playing as Thel 'Vadamee. Often, waypoints have a distance indicator, in meters, showing the player how far away the waypoint is from their position.