By convention, all standard electrode potentials are reduction potentials. A positive value suggests that the reduced form of the species is more stable than hydrogen gas and a negative value suggests that the hydrogen gas is more stable than the reduced form of species. Here, the reduced form (Zn) is not stable. It is difficult to reduce Zn²⁺ to Zn. So, the reverse is more likely to happen. Zn would rather get oxidized to Zn²⁺ and H⁺ will get reduced.

Thus, Zn is more reactive than Hydrogen.