A cherub is a category of angel usually depicted in modern times as a winged infant. In actuality, it is called a putto (plural: putti) while the actual cherubim of Abrahamic religion are of uncertain appearance.

According to the Jewish angelic heirarchy, the cherubim are ranked ninth among the angels (putting them as the second-lowest ranking, above only the human-like Ishim, while Kabbalistic works put them in the third rank. Christianity places them in the highest rank along with the Seraphim and the Thrones while Islam refers to them as the highest angels, those directly attending God Himself.

Their actual original appearance is uncertain, having been lost to time, but comparisons with neighboring groups indicate that the cherubim looked like winged sphinx, a lion body with eagle wings and a human head. In the Biblical Book of Ezekial, they are portrayed as tetramorphs, four-headed (man, ox, lion, and eagle) eldritch abominations with four wings covering their bodies.

In Renaissance religious art, the term cherub began to be associated with putti, usually winged young male children once symbolically associated with profane passions. Modern depictions of cherubs are actually putti mixed with Cupid. A putto that obviously represents a cupid is known as an amorino (plural: amorini) or amoretto (plural: amoretti).

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Cherub (Wikipedia)
Putto (Wikipedia)