Question

I often see web developers use the following:

*, html {
    margin: 0;
    padding:0;
}

But I would have thought that would be redundant, since * matches all elements. Am I missing something here?

Answer 1

It isn’t redundant if you are in need of more specificity to protect from an override default style on an html selector maybe such as in the case of changing font styles.

However, * will match an html tag.

You can read more about CSS Specificity here.

Edit:

Example case usage:

if you have a default set of styles you include on every page to override browser defaults that includes this:

*,html {
   margin: 0;
   padding: 0;
}

then later a different css file happens to have the same selector for a different case:

* {
   margin: 10px;
   padding: 0;
}

Then your html will remain unaffected because a * has no specificity for starters which means the rule is overturned by the previous css rule.

I added a font changing example that does this on the body tag to demonstrate the concept – http://jsfiddle.net/M89Tn/1/