A definition of the Nav Mesh Agent components

To use a Nav Mesh Agent to make an enemy follow the player, you first have to open window/navigation and drop it next to the inspector, I got that. But I'm very confused what the different components in a Nav Mesh Agent and in the navigator really does. I have already made a capsule collodier which detects collisions correctly, but if I select the enemy I want should follow the player, having selected the enemy and varying the size of the components have no visual effect on the circles around the enemy as a capsule collider would, so I'm very confused what they really does. Could someone please give me an explanation of what the components: Radius, Height, Base Offset, Speed, Angular Speed, Acceleration, Stopping Distance from the Nav Mesh Agent does, the definition of Agent and Nav Mesh from the game screen and what Agent Radius, Agent Height, Max Slope, Step Height, Drop Height, Jump Distance, Voxel Size, Min Region Area, Height Mesh and most importantly Bake from Navigation and Bake really does and how to adjust the size of the nav mesh. The best would be a short from the book definition of what they do indiviudally. Thank you.

 

http://docs.unity3d.com/Manual/class-NavMeshAgent.html