What is the difference between combustion and oxidation? Under what conditions an oxidation reaction becomes combustion?

Explanation

Addition of oxygen or removal of hydrogen from any substance is called oxidation. E.g.,
`CH_(3)CH_(2)OH+3O_(2)rarr2CO_(2)+3H_(2)O`
However when ethanol is heated with alkaline `KMnO_(4)` it gives ethanoic acid.
`CH_(3)CH_(2)OH+2[O]underset(KMnO_(4))overset("alk")rarrCH_(3)COOH+H_(2)O`
Both these reactions are oxidation reactions because in both cases oxygen has been added or hydrogen has been removed. But complete oxidation of compound to form `CO_(2)andH_(2)O` is called combustion which is generally accompanied by evolution of heat energy, e.g.,
`C_(2)H_(6)+7/(2)O_(2)rarr2CO_(2)+3H_(2)O+"Heat energy"`
While only partial oxidation of a compound is called oxidation.