Electricians: What is pure sine power inverter vs regular 12v power inverter?

i have a 400 and 1000 watt 12v inverters in each of my truck. i hook up lights, cordless drill chargers, corded tools, nothing special and no complaints. but i hear people talking about pure sine wave power inverter and i was wondering what is it and how do i benefit from it?
2 answers 2