Zero-based budgeting requires all expenses to be justified for each new period, starting from zero rather than using the previous budget. It differs from traditional budgeting by being decision-oriented and focusing on cost-benefit analysis rather than just monitoring expenditures. The zero-based budgeting process involves setting objectives, identifying operational areas, developing decision packages, performing cost-benefit analyses, selecting packages, and finalizing the budget. It aims to efficiently allocate resources but can be time-consuming and force justification of all expenditure details.