Updated: 12/09/2018 by Computer Hope

Em may refer to any of the following:

1. EM is an abbreviation for electromagnetic or electromagnet. For example, "The sound wave had an EM frequency of ten thousand Hertz."

2. With HTML (hypertext markup language), the <em> tag (short for emphasized) is used to give emphasis to a certain block of text. Emphasized text is often displayed in italics, like this.

3. Em is a typeface measurement that was originally defined as a measurement between the top and bottom of the capital "M." However, today an em is a dynamic measurement based on the point size value of the font size property. For example, in CSS (cascading style sheets), if you set the font size of H1 to 1.2em, its text size would be 20% greater than the font size it inherits from the parent element or default font property. See our em space definition for more information.

4. When used in chat, "'em" is chat slang for them.

Block of text, Chat terms, Computer abbreviations, Font, Measurement, Typography terms