Final answer:
The scenario described where every transaction has at least one debit and one credit is known as the Dual Entry System, which is a fundamental principle of accounting.
Step-by-step explanation:
When every transaction has at least one debit and one credit, it is called a Dual Entry System. This system of accounting is based on the fundamental principle that each transaction is recorded by equal and opposite entries to the accounts. For example, if a company buys office supplies for cash, the cash account would be credited (since cash is leaving the company), and the office supplies account would be debited (since supplies are being added).