Fanout is especially useful for quickly connecting multiple components to ground.
Device fanout traces a short distance from each pad of the device, then drops a via.
Signal fanout tries to add a via from each pad along the signal path, subject to design rule violations.
Ball Grid Array (BGA) Autorouter has additional settings for elements and signals.
Style settings control whether vias are placed on the outside, inside, or alternating sides of device pads or signal path.