Hollow tine aeration is carried out by a machine that is wheeled over the lawn which pulls out thousands of tiny cores of soil (plugs) all over the lawn.  They are evenly spaced out across the lawn about every 3 inches.  Each hole is around 2 to 3 inches deep and about a half inch wide.

Doing this relieves the compaction in the lawn, enabling water to drain to the roots easier as well as key fertilizer nutrients.  Overall it helps produce a happier healthier lusher lawn.