Bookkeeping Fundamentals: Double Entry & Petty Cash Imprest System 📊

### No document, no transaction! In accounting, every transaction must have physical or digital evidence: * **Invoice**: A bill sent to a buyer showing goods sold on credit and amount owed. * **Receipt**: Written acknowledgment that payment in cash or bank transfer was received! * **Petty Cash Voucher**: A small slip authorizing payment for minor daily office expenses (e.g. postage stamps, broom, tea supplies).