em
ఎం
definition
noun
From there, sizing descendant elements with ems (a relative unit of measurement) becomes much more logical: 1em is 10 px, 1.6em is 16 px, .9em is 9px, and so forth.
a unit for measuring the width of printed matter, equal to the height of the type size being used.
abbreviation
electromagnetic.
example
So, a font size of 1.25 'ems' will be displayed as 1.25 pixels.
It doesn't matter which unit you use - zero horseshoes is the same as zero pixels, 'ems' , or percentages.
This reduced the text to an unreadable level when the CSS specified sizes in 'ems' , but only reduced it slightly when specified as percentages.
From there, sizing descendant elements with 'ems' (a relative unit of measurement) becomes much more logical: 1em is 10 px, 1.6em is 16 px, .9em is 9px, and so forth.
Sterne was almost compulsively attentive to page layout and typography, going so far as to specify the length of each dash in printer's 'ems' .
Credits: Google Translate
