Thermal death time - The shortest time to kill a suspension of organisms at a specific temperature. The lowest temperature to kill a suspension of organisms in a given time. Moist heat - Acts by denaturation and coagulation of proteins. Boiling - Vegetative forms are killed in minutes. However, its unreliable sporicidally.
Latent heat is released when steam condenses on a cold surface causing proteins to coagulate.
There should be indicators to check for sterility. It is slow and requires a higher temperature for sterilization than moist heat.