Do you ever wonder why you are asked to turn off mobile phones and electronic games in an aircraft or hospital, where there are a host of other electrical and electronic systems on which many people's lives may depend?
Or is your favourite radio programme obliterated by interference? TV screen covered in 'snow' when someone uses an unsuppressed vacuum cleaner or electric drill nearby? Most of the older generation will still remember such problems, even if today (thanks in part to IEC International Standards) they very largely have been overcome.
Examples like these illustrate what is called electromagnetic compatibility (EMC).