In general, oxidation is the loss of electrons and reduction is the gain of electons. When something is oxydized, the oxidation number will increase and when something is redu
…ced the oxidation number will decrease. Oxidizing agent (oxidant) is a species which causes another to be oxidized. Reducing agent (reductant) is any species that causes another species to be reduced. A common example of oxidation is when oxygen in water combines with an element in an object. When metal rusts it is usually caused by the oxygen in water combining with the metal (usually the iron in steel) to form iron oxide or some other "oxide". When burning organic material such as wood the technical term for fire is "rapid oxidation", because what is happening is the oxygen atoms are breaking apart carbon atoms from their molecules and bonding with them (because oxygen and carbon bond more easily) and the chemical breaking and bonding is releasing enough heat energy to break more carbon loose, then it keeps bonding with the oxygen in the air to form carbon dioxide, carbon monoxide etc, "fueling the fire" until there is not enough heat to break up more carbon molecules, or there is no more oxygen for it to bind with, which is why putting a glass over a candle will put it out. The oxidation in rust is the same thing, just with different elements and much too slow to give off noticable heat or sustain a chemical reaction. (MORE) 
