EMI / RFI is short for Electromagnetic Interference / Radio Frequency Interference. Technically, both terms refer to the same phenomena of electromagnetic waves affecting the operation of electronic devices, and often the terms EMI and RFI are used interchangeably because radio waves are simply a subset of the electromagnetic spectrum. In practice, however, EMI generally refers to shorter wavelength high-energy emissions and RFI refers to longer wavelength low-energy emissions. EMI issues are commonly short-range package or board-level issues but may also be present because of 5G transmitters or powerlines. RFI issues are generally longer-range issues between devices or between a device and a background environment.
EMI / RFI is a growing issue in the modern world. Radio, cell phone, and Wi-Fi transmitters permeate space with signals. Power lines near homes and offices are increasingly concerning, and environmental emissions are becoming increasingly powerful, especially with the development of 5G technology. As electronics devices become smaller and more sensitive, they become more susceptible to external interference, compounding the problem. Additionally, more and more people are concerned about the possible health concerns of long-term exposure to high-energy electromagnetic waves. As a result, EMI / RFI shielding is increasingly important.