Which of the following statement is correct about resonance and resonating structures?

To determine the correct statement about resonance and resonating structures, let us analyze each of the given options step-by-step:

1. Resonating structure with more covalent bonds is more stable:
In resonance, canonical structures that have a greater number of covalent bonds are generally more stable because bonding is an exothermic process that lowers the potential energy of the molecule. The more bonds that are formed, the greater the release of energy, which leads to increased stability. Therefore, this statement is correct.

2. The resonance structures differ in position of electrons and relative position of atoms:
Resonating structures (canonical forms) must have the exact same relative positions of the atomic nuclei. They differ only in the arrangement or distribution of electrons (specifically π-electrons and non-bonding/lone pair electrons). Any structures that differ in the positions of atoms are isomers (such as tautomers), not resonating structures. Thus, this statement is incorrect.

3. The stability of resonance hybrid decreases with increasing number of equivalent resonating structures:
The resonance energy increases (which means stability increases) as the number of equivalent resonating structures increases. For example, the carbonate ion (${\mathrm{CO}}_3^{2-}$) has three equivalent resonating structures, which makes it highly stable. Thus, this statement is incorrect.

4. Electronegative atom bearing positive charge in the canonical form is more stable:
Electronegative atoms (like oxygen or nitrogen) are highly electron-withdrawing and prefer to hold a negative charge. canonical structures in which a highly electronegative atom bears a positive charge are generally less stable, unless every atom in the structure satisfies the octet rule. Thus, this statement is incorrect.

Conclusion:
The only correct statement is that the resonating structure with more covalent bonds is more stable.