* all elements
div all div tags
div,p all divs and paragraphs
div p paragraphs inside divs
div > p all p tags, one level deep in div
div + p p tags immediately after div
div ~ p p tags preceded by div
.classname all elements with class
#idname element with ID
div.classname divs with certain classname
div#idname div with certain ID
#idname * all elements inside #idname