What is the difference between oxidation and reduction?

Oxidation and reduction are considered opposites in terms of electrons moving. Oxidation occurs when an electron is lost, while reduction occurs when an electron is gained. It is often seen with oxygen being gained (why it's called oxidation).An example can be seen in the extraction of iron from its ore: Fe2O3 + 3CO = 2Fe + 3CO2In this case cabon monoxide is oxidised and iron is reduced.
A common method to remember this is OIL RIG:OxidationIsLoss of electrons
ReductionIsGain of electrons