This is the angle of degrees the line you will be traveling is from magnetic north. If it doesn t make sense don t worry, its not that important. What is important is if the guide book you have been following says to travel at a bearing of 291 degrees, you know to rotate the housing so that 291 lines up with the front or top sighting line, move the compass and yourself until the needle aligns with the orienting needle, and you follow the sighting lines. Maps Maps are two dimensional representations of three dimensional features. Its a flat drawing of a changing world.
Topographical maps are the standard map for most navigating.
Scale Scale is a representation of the size of a feature on the map relative to the size of the real thing. For example a lake measuring 1 centimetre on a map with a scale of 1to 50,000, would represent an actual lake 50,000 centimetres or 0.5 kilometres wide. Whether you measure in inches, feet, centimetres, or thumb nails, the relationship is still the same. Used by hikers, ski tourers, and backpackers on longer trips in more moderate terrain. Limited detail with no information regarding mico-terrain features need for ground travel.