CSS question

I came across a site that had some CSS code that I didnt understand today, I thought I had a pretty good understanding of how everything works before today but this guy opened my eyes to a few new things…. first I found out from his site that you can do wildcards in CSS, something before today I thought impossible… [class*=”span”]

but I came across another tag I dont understand yet… its a simple small tag but not in the fontsize format that I know. He had it wrote out as this:

h1 small{ color...}
h2 small{...}
h3 small{...}
p small {...}

He had a few more places where he did this… having never seen it before and as far as I remember the only place Im aware of seeing small in css was in the font-size:small, smaller etc type of format.

Anyone know what this is for?