How does revenue affect the balance sheet?

The place where you normally see revenue is at the top of the income statement.

However, it also has an impact on the balance sheet. If your payment terms are cash only, then revenue also creates a corresponding amount of cash on the balance sheet. If your payment terms allow credit to customers, then revenue creates a corresponding amount of accounts receivable on the balance sheet. Or, if you are making a sale in exchange for some other asset (which occurs in a barter transaction) then some other asset on the balance sheet might increase.

This increase in assets also creates an offsetting increase in the stockholders' equity part of the balance sheet, where retained earnings will increase.