Waypoint
A node in a hand-placed or generated graph marking a walkable spot; the classic pathfinding method before the navmesh.
A waypoint graph is a set of nodes dropped around the level with edges saying "from here you can reach there". A* or Dijkstra searches the graph like any other, and the character follows the nodes in sequence. The method dominated bot and enemy AI through the 1990s and early 2000s; the bots in Quake and Counter-Strike navigated on hand-placed waypoints.
The weakness is that the graph only knows its own points — a character shoved off an edge has no idea how to get back, and the motion often looks like it is snapping to invisible rails. The navmesh, which describes the whole surface rather than isolated points, largely took over during the 2000s. Waypoints survive for patrol routes and scripted paths.