Zero-based budgeting (ZBB) is an approach to budgeting that involves building a budget from the ground up, starting with a zero base for each budgeting period. In both personal finance and organizational contexts, this means that every expense must be justified and approved, regardless of whether it was included in previous budgets.

Cash flow budgeting is a financial management approach that focuses on tracking and managing the actual inflows and outflows of cash in a given time period. This budgeting method is particularly useful for individuals, businesses, or organizations to understand how money is moving in and out of their accounts, ensuring they have enough liquidity to cover their financial obligations.

The debt avalanche method is a debt repayment strategy that involves prioritizing and paying off debts based on their interest rates. In this method, you focus on tackling the debt with the highest interest rate first, making larger payments towards it while paying the minimum on other debts.

The debt snowball method is a debt repayment strategy that involves paying off debts in a specific order, starting with the smallest balance and progressing to the largest. In this approach, you focus on eliminating the debt with the smallest outstanding balance first, regardless of the interest rate associated with each debt.

The 50/30/20 rule is a budgeting principle that recommends dividing your after-tax income into three main categories: allocate 50% to essential needs such as housing and utilities, 30% to discretionary wants like entertainment and dining out, and reserve 20% for savings and debt repayment, encompassing contributions to savings accounts, retirement funds, and debt reduction.

The envelope system is a budgeting method that involves allocating and managing cash for different spending categories using physical envelopes. This system is designed to help individuals and households control their spending, prioritize financial goals, and avoid overspending in specific areas.

The Pareto Principle, commonly known as the 80/20 rule, suggests that roughly 80% of results often come from 20% of causes or efforts. It highlights the disproportionate relationship between inputs and outputs, emphasizing that a small portion of factors typically contributes the most to outcomes. Applied in various fields, including personal finance, it helps identify crucial areas for focus, resource allocation, and optimization to achieve more significant impact with less effort.