What is the difference between commuter rail and light rail?

Commuter Rail	Light Rail
Powered by 25kV alternating current overhead electrical system	Powered by 750 V direct current by overhead electrical system
Typically serves longer lines with fewer stations	Can operate along crowded, narrow streets
Can operate up to 79 mph	Can accelerate and decelerate quickly; top speed 55 mph
Capacity of 90 seats, 142 standing	Capacity of 64 seats, 121 standing

Train Technology Comparison