Why the assets and laibilities sides of balance sheet is equal?

Accounting is based on the formula of Assets = Liabilities + Owner's Equity.

the DR side of a balance sheet are the Assets while the CR side records Liabilities & Owner's Equity. Hence for the formula to be effective, both side of the balance sheet must be equal (balance).

PS: It's not the asset and liabilities side but rather the Debit and Credit side.