Margin and padding using em

Question

When 1em is applied to an element, it takes the default value of the browser (usually, 16px) or the font-size value of its parent, right?. But I noticed that if I use something

Answer 1

1em is equal to the font-size of the element in question. So when using it with margins, it will be equivalent to the font-size of the element you're applying the margin too.