Strainer is a hypernym of colander.

As nouns the difference between colander and strainer

is that colander is a bowl-shaped kitchen utensil with holes in it used for draining food such as pasta while strainer is a device through which a liquid is passed for purification, filtering or separation from solid matter; anything (including a screen or a cloth) used to strain a liquid; any device functioning as a sieve or filter - in special, a perforated screen or openwork (usually at the end of a suction pipe of a pump), used to prevent solid bodies from mixing in a liquid stream or flowline.