Every entry in the accounting book has an impact either on the debit side or on the credit side of the account. What comes in is credited and what goes out is debited.
Explanation:
With the investment made by the company for common stock, cash will be debited and the stocks will be credited. With supplies being purchased, cash again is debited and the supplies are entered on the credit side of the account book.
With land purchased, land is credited and the cash is again debited because it goes out of the company. With additional supplies purchased, assets in the form of purchase of supplies are increased but the liabilities also increase by the same amount because of the credit.