What is Balance?

Legal Definition
In banking and accountancy, the outstanding balance is the amount of money owed, (or due), that remains in a deposit account.

"Balancing the books" refers to the primary Balance sheet equation of A=L+OE, or Assets=Liabilities plus Owner's Equity. The first "balancing" of books, or of the balance sheet financial statement in accounting is to check iterations (test balances) to be sure the equation above applies, and where Assets and Liabilities are unequal, to equalize them by debiting or crediting Owner's Equity (i.e. if assets exceed liabilities, equity is increased, if liabilities exceed assets, equity is decreased, both in the amount needed to balance the equation).

In addition to the balance sheet, the other primary financial statement (the P&L or Profit and Loss Statement) also is balanced against the balance sheet, generally by use of a "plug" such as imputed interest.
-- Wikipedia
Legal Definition
Com. law. The amount which remains due by one of two persons, who have been dealing together, to the other, after the settlement of their accounts.

2. In the case of mutual debts, the balance only can be recovered by the assignee of an insolvent, or the executor of a deceased person. But this mutuality must have existed at the time of the assignment by the insolvent, or at the death of the testator.

3. The term general balance is sometimes used to signify the difference which is due to a party claiming a lien on goods in his hands, for work or labor done, or money expended in relation to those and other goods of the debtor. 3 B. & P. 485; 3 Esp. R. 268.
-- Bouviers Law Dictionary
Legal Definition
The amount remaining due from one person to another on a settlement of the accounts involving their mutual dealings; the difference between the two sides (debit and credit) of an account. A balance is the conclusion or result of the debit and credit sides of an account. It implies mutual dealings, and the existence of debt and credit, without which there could be no balance. Loeb v. Keyes, 156 N. Y. 529, 51 N. E. 285; McWilliams v. Allan, 45 Mo. 574; Thillman v. Shadrick, 69 Md. 528, 16 Atl. 138. The term is also frequently used in the sense of residue or remainder; as when a wlll speaks of "the balance of my estate." Lopez v. Lopez, 23 S. C. 269; Brooks v. Brooks, 65 III. App. 331; Lynch v. Spicer, 53 W. Va. 426, 44 S. E. 255. See Balance-sheet.
-- Black's Law Dictionary
Legal Definition
The remainder due a party after settling accounts with another. See 156 N. Y. 529, 51 N. E. 285.
-- Ballentine's Law Dictionary