Normal Balances

Each account has a normal balance (either Dr or Cr). The normal balance is the balance that the account normally sits in and it is the type of journal entry needed to increase the account.

Normal Balances are the same within each accounting element. Accounts with a Normal Debit Balance are:

Assets

Drawings

Expenses

Accounts with a normal credit balance are

Liabilities

Owners' Equity

Capital Introduced

Revenue

This fits with the accounting equation A=L+OE so that Drs (assets) equal the credits (Liabilities and Owners Equity). Anything that increases Owners' Equity (Capital Introduced and Revenue) will also have a normal balance of a credit. Whereas anything that reduces owners' equity (Drawings and Expenses) will have a normal balance of a Debit.

The page on Debits and Credits explores this further