A bearing is a direction expressed as an angle in degrees clockwise from north (0–360°), used to navigate from one point to another. You can take a bearing off a map and follow it with a compass, or sight a bearing to a landmark in the field — the core skill of map-and-compass navigation.
Map scale is the ratio between a distance on the map and the corresponding distance on the ground, written as a ratio such as 1:24,000 (one unit on the map equals 24,000 units in reality). A smaller second number means a larger-scale, more detailed map covering less area; scale lets you measure real distances and plan travel time.
A contour line on a topographic map connects points of equal elevation, so the pattern of lines reveals the terrain's shape and steepness. Lines close together indicate steep ground; lines far apart indicate gentle slopes. The contour interval — the elevation change between adjacent lines — is given in the map's legend.
A topographic map (topo map) represents three-dimensional terrain on paper using contour lines that connect points of equal elevation, letting you read the shape, height, and steepness of the land. Combined with a compass, it's the foundation of backcountry navigation, showing peaks, valleys, slopes, water, and trails.