Radiation

It is a way of transferring heat from one area to another without any medium to carry the heat.

Radiation is the mode of heat transfer that takes place when you take your hands close to a set fire.

You do not touch the fire but after sometime your palm becomes hot. In radiation, the hotter object is not in direct contact with the colder object.

Another typical or common example of radiation is the transfer of heat from the sun to the earth. Since radiation does not require a material medium, it can take place in a vacuum.

A vacuum is an empty space with no matter present.