The name Cherubim is plural and refers to more than one Cherub angel. You will occasionally see the plural version referred to as Cherubs, however the correct pronunciation is Cherubim. These angelic entities are a powerful class of supernatural beings. Within the Christian angelic hierarchy, the Cherubim rank as the second highest order of angels, just under the Seraphim. In the Jewish angelic hierarchy, the Cherubim are listed as the ninth rank of angels out of ten, placing them well at the bottom. The Cherubim often appear in Renaissance artwork, and are very often confused with putti angels, the little winged infant like children seen holding a golden trumpet. The actual Biblical description of these beings is quite the opposite of putti angels, with a Cherub being a huge fearsome winged beast, and guardian of the gate of Eden. In a literal sense, they are almost like spiritual or angelic Grenadier Guards, not small child like angels.
Within the Christian Bible, it mentions the Cherubim angels over 100 times. They are usually presented as a huge, hybrid creature possessing eagle wings, human faces, and the half body of a lion and an ox. The prophet Ezekiel in his vision of God's Throne, saw four mighty Cherubim standing guard. Each of them had two pairs of wings, and when Ezekiel stepped forward towards them, he heard the rustle of their wings which sounded to him like flowing water. Like the voice of God, this sound of Cherubim wings was almost deafening to Ezekiel, who had to shield his ears from it. Ezekiel also goes on to describe the Cherubim bodies, which in his recollection were covered with thousands of eyes that covered their shoulders, arms, and wings. The prophet said that in each of these many eyes, was the all knowing truth and knowledge of God. If you are interested in reading more about this, see Ezekiel Chapter 10, verse 12 of the Bible.
According to some theologians, the Cherubim govern the material world. The Bible also adds that they function as guardians of Eden still to this day, a sacred place which is home to the tree of life. Theologians have also noted that the Cherubim very likely predate Judaic scripture, as similar creatures have been found in stone carvings scattered around Egypt and Mesopotamia. Ancient Jews of the Biblical era had frequent interaction with other civilizations through trade and conquest, and it is thought that the concept of the Cherubim many have been pagan in origin. To give Jewish religious figures credit where it is due, they are solely responsible for introducing the Cherubim to modern civilization, regardless of whether or not the creatures had an older past. I will say that some scholars dispute the origin, claiming that Jewish scripture is indeed the original source, and that these stone carvings are not the same creatures.
With regard to the confusion between Cherubim and putti angels, you will probably have noticed that the confusion is so widespread, that it is unlikely to ever be corrected. In fact, it's a great example of a huge error that has been widely accepted by the majority of society, regardless of the fact that it's blatantly incorrect. For the record, Cherubs are not the small winged infant like angels that you see everywhere, despite the fact that the ignorant masses call them that. Cherubs itself isn't even the correct plural spelling, it's Cherubim, and these creatures are might multi headed beasts, not little Renaissance style child like angels. Those Renaissance painters clearly knew nothing of Christian religious scripture, and thus left to their own interpretation of certain Biblical creatures, they managed to totally ruin one of them via mass confusion. Wouldn't be the first time though, look at how they generally depicted God as a bearded man.