what is full form of em in css
Em (typography) In Cascading Style Sheets, the em unit is the height of the font in nominal points or inches. The actual, physical height of any given portion of the font depends on the user-defined DPI setting, current element font-size, and the particular font being used.
Electromagnetic radiation In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space, carrying electromagnetic radiant energy.[1] It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays.[2]