Answer:
A non polar bond is one in which neither element in the bond is more positive or negative than the other, that is, the elements have an equal pull on the electrons.
In a covalent bond, the elements share electrons between them, but in most bonds, one pulls more strongly than the other, bringing the electrons closer to that element and giving that element a slightly negative charge, for example in the O-H bond. This makes the other end slightly positive and makes it a polarized bond.
In a non polar bond, there is no negative or positive end because the elements both pull the electrons with equal strength. This is exhibited in diatomic molecules such as O2, as both oxygens have equal pull on the electrons. Bonds with extremely low polarity are also functionally non polar.