wt is disproportionation ?

Disproportionation is the reaction in which both oxidation and reduction of the same element occurs.
In Chemistry, disproportionation is known as 「歧化」. It should NOT be translated in a layman manner.

Example 1 :
Chlorine gas reacts with cold sodium hydroxide solution.
Cl2(g) + 2OH-(aq) → Cl-(aq) + OCl-(aq) + H2O(l)
Cl2(g) undergoes oxidation as the oxidation state (or oxidation number) of Cl increases from 0 to +1 (in OCl-).
Cl2(g) also undergoes reduction as the oxidation state of Cl decreases from 0 to -1 (in Cl-).
Therefore, Cl2(g) undergoes disproportionation.

Example 2 :
Heat the solution of NaOCl formed in Example 1.
3OCl-(aq) → ClO3-(aq) + 2Cl-(aq)
OCl-(aq) undergoes oxidation as the oxidation state of Cl increases from +1 to +5 (in ClO3-).
OCl-(aq) also undergoes reduction as the oxidation state of Cl decreases from +1 to -1 (in Cl-).
Therefore, OCl-(aq) undergoes disproportionation.

I don't really think Uncle Michael is trying to say redox is the same as disproportionation in his answer.

給nayeohnahc~~
Uncle Michael雖然答得好長盡..但係你要知道,disproportionation同redox係兩樣野.唔好俾oxidation & reduction simutaneously 而以為disproportionation 係redox

disproportionation = 不均衡, 不相稱