Often the terms air cleaner, air filter and air purifier are used interchangeably. Strictly speaking, however, they are different.
An air filter or air cleaner is a filtering device that uses certain filters, such as a HEPA or activated carbon filter, to filter pollutants, allergens, gases or aerosols from the air and collect them inside.
An air purifier eliminates pollutants and pathogens by UV-C light, ionization or the risk-free photocatalysis with UV-A light. Depending on the device, by-products such as ozone and formaldehyde are eliminated, or no emissions at all, as is the case with the AiroDoctor.