What are oxidation and reduction on the basis of change in oxidation number ?

In redox reactions, oxidation and reduction occur simultaneously . How are oxidation and reduction related to the oxidation number ?

The chemical that undergoes self oxidation and self reduction in the same reaction is

Assign oxidation number B in NaBH_4

Which of the following statement is not, correct? : Oxidant is a substance which increases the oxidation number of other substance, Reductant is a substance which decreases the oxidation number of other substance., The oxidation number of oxidant decreases, In oxidation there is decrease in oxidation number.

Assign oxidation number Mn in KMnO_4

Some rules related to oxidation number are given below. Correct the mistake. Oxidation number of hydrogen is always +1

Write the equations of the oxidation and reduction reactions.