Explain the redox reaction of electrodes with the example of a Daniell cell.

(N/A) In a Daniell cell,a zinc rod is dipped in a $ZnSO_4$ solution and a copper rod is dipped in a $CuSO_4$ solution.
At the interface of the metal and its salt solution,both the reduced and oxidized forms of the same species are present. $A$ redox couple is defined as the oxidized and reduced forms of a substance taking part in an oxidation or reduction half-reaction.
This is represented by separating the oxidized form from the reduced form by a vertical line or a slash. For example,the two redox couples are represented as $Zn^{2+}/Zn$ and $Cu^{2+}/Cu$.
The two solutions are connected by a salt bridge,which is a $U$-tube containing an electrolyte like $KCl$ or $NH_4NO_3$ in an agar-agar jelly.
When the zinc and copper rods are connected by a metallic wire,the following observations are made:
$(i)$ Electrons flow from the $Zn$ rod to the $Cu$ rod through the external metallic wire.
$(ii)$ The circuit is completed by the migration of ions through the salt bridge,maintaining electrical neutrality.
The potential associated with each electrode is known as electrode potential. When the concentration of each species is $1 \ M$ and the temperature is $298 \ K$,it is called the standard electrode potential $(E^{\ominus})$.
By convention,the standard electrode potential of the hydrogen electrode is $0.0 \ V$. $A$ negative $E^{\ominus}$ value indicates that the redox couple is a stronger reducing agent than the $H^{+}/H_2$ couple.