em = relative to parent element fontsize
rem = relative to root fontsize of html
'em' units for the font-size property will be relative to the'font-size of the parent element'.
'em' units on other properties other than font-size will be relative to the
font-size of the current element. 'rem' units sizes will always be relative
to the font-size of the root html element.
em -> Relative to the font-size of the element
(2em means 2 times the size of the current font)
Relative Units: changes upon screen measurements.
n % => counts on parent elements, for example if we have a parent of 500 px, so the 50% will be 250px
n vw => 1% of widths, total pixels
n vh => 1% of heights, total pixels.
vmax => maximum of height or width
vmin => minimum of height or width viewport
n em => n x (parent element’s font size)
n rem => n x (HTML’s font size)
/*realative to the font-size*/