On the Be-1900 (PT6-A), we have six levers.
First are the power levers which control fuel to the engines through the FCU, thus controlling engine torque (power). The power levers also control the beta valve which changes the low pitch stop for the propellers. Basically, beginning with ground idle and moving the levers aft toward reverse, the power levers control both prop pitch and fuel to the engines. The power levers are used to control the engines from full reverse, through ground fine, ground idle, and all the way to max power.
Next to the throttles are the propeller levers which control prop RPM basically through a govenor setup like you see in reciprocating engines. The prop levers are set to taxi for ground ops, are full forward (1700 RPM) for T/O and landing, and generally we pull the props back to around 1500-1550 for cruise.
Lastly we have the condition levers which basically adjusts the idle speed of the engine from 65% N1 to 72% N1. Normally, the condition levers are set to the low idle setting and are not touched for the duration of the flight. They are basically used for starting and shutting down the engines.