What process is referred to as heating by direct contact?

The process referred to as heating by direct contact is conduction. This is the mechanism through which heat is transferred between materials that are in direct physical touch with each other. When one object, at a higher temperature, contacts another object, the heat energy flows from the warmer object to the cooler one until thermal equilibrium is achieved. This transfer of heat occurs at the molecular level as faster-moving molecules in the warmer object collide with slower-moving molecules in the cooler object, imparting energy to them.

In contrast to conduction, convection involves the movement of fluid (liquid or gas) where warmer areas of a liquid or gas rise and cooler areas sink, creating a cycle of heat transfer. Advection is a specific form of convection that refers to the horizontal movement of air, typically used in meteorology. Radiation is the transfer of heat in the form of electromagnetic waves, such as infrared radiation, and does not require direct contact between objects. Each of these processes is distinct, with conduction specifically characterized by direct physical contact for heat transfer.