The quality of being hot; high temperature: "it is sensitive to both heat and cold"

is the movement of heat from one place to another

THE MOVEMENT OF HEAT THROUGH DIRECT CONTACT

THE MOVEMENT OF HEAT IN CIRCULATION OF AIR

HEAT MOVING IN THE FORM ELECTROMAGNETIC WAVES THROUGH THE AIR

TOUCHING A STOVE, COOKING EGGS

HEATING WATER IN A POT, HEATING A LARGE ROOM

THE SUN HEATING THE EARTH, ROASTING A MARSHMALLOW