In the case of electromagnetic waves, we distinguish between ionizing and non-ionizing radiation. The term radiation refers to the frequency of an electromagnetic wave. Ionizing radiation (which we do not use for wireless communication at very high frequencies) has enough energy (quantum energy) to ionize molecules in the human body and could damage cells and the hereditary information in chromosomes – naturally, depending on the level of exposure.
At the frequencies we use in wireless communications, the quanta of energy are over a million times smaller, so it is considered to have no ionizing effects. For this reason, such radiation is called ‘non-ionizing’.