Navigation components

The short answer is that Unity has spent a lot of time perfecting their navigation system and delivering components that we can use to govern how playable and non-playable characters can get around. Each of the following components comes standard with Unity and has complex features already built-in:

• A NavMesh is essentially a map of the walkable surfaces in a given level; the NavMesh component itself is created from the level geometry in a process called baking. Baking a NavMesh into your level creates a unique project asset that holds the navigation data.
• If NavMesh is the level map, then a NavMeshAgent is the moving piece on the board. Any object with a NavMeshAgent component attached will automatically avoid other agents or obstacles it comes into contact with. 
• The navigation system needs to be aware of any moving or stationary objects in the level that could cause a NavMeshAgent to alter their route. Adding NavMeshObstacle...