130 mOhm on-resistance — the conduction loss number
That 10 V drive voltage is the recommended level for minimum Rds(on); at lower gate voltages the resistance climbs, so the gate supply rail needs to deliver a clean 10 V for the MOSFET to hit its rated efficiency.
Through-hole TO-220 — mounting and thermal path
Maximum power dissipation is 190 W at case temperature, but that figure assumes the tab is bolted to an infinite heatsink — real-world dissipation depends on the thermal interface and airflow. The tab is electrically connected to the drain, so an insulating pad or thermal compound is needed if the heatsink is grounded.
The base product number STP33 covers a family of voltage and current variants sharing the same footprint, which helps with second-sourcing within the same series.