Power MOSFET is a specific type of metal oxide semiconductor field-effect transistor (MOSFET) designed to handle large amounts of power. The metal oxide semiconductor field effect transistor (MOSFET) is based on the original field-effect transistor introduced in the 70s. Beside diagram shows the device schematic, transfer
characteristics and device symbol for a MOSFET.
The following file contains detail explanation on The Basic Theory of Power MOSFET written by Vrej Barkhordarian from the International Rectifier, Ca. Herein you will get description on the power MOSFET breakdown voltage, on-resistance, transconductance, threshold voltage, diode forward voltage, power dissipation, dynamic characteristics, gate charge, and dV/dt capability. (source: irf.com)