When you breathe does the lungs go and get bigger or smaller?

When you breath in (inhale) - they expand - become larger.
When you breath out (exhale) they become smaller.
when you inhale your lungs expand (gets bigger). when you exhale, your lungs contrast (gets smaller)
breath contained by lungs expand
breath out lungs shrink back
Bigger or expand, because in that is air innards them