Pls what are <em> elements

Question

in css

Answer 1

<em> means emphasis. It bolds or italicises text (depending on the browser) and modifies how text-to-speech reads it.

Answer 2

If you write '<em>' you should talk about html element...
Iy you're talking about css, 'em' is an particular units relative to the font-size: 'em' stand for Espacement of letter M, and is less or mor equivalent to the height of the font. So a font-size of 2em would make the font size growing by two... Another equivalent unit is 'ex' ( for espacement of x ).