el
el
#id
el el    plate apple
#id el   #fancy apple
.class
el el.small
el.small
el,el
*
plate *     everything on a plate
plate + apple
bento ~ pickle
plate > apple





el > el  el is direct child

el + el (immediately preceded)
el ~ el (preceded by)

:first-child
:only-child
:last-child




- combine # and . selectors
- combine .className.className selector
- .plate:not(:empty)
