A defense budget is the portion of a government's budget allocated for military and defense-related expenses. This includes funding for personnel, equipment, operations, and maintenance of the armed forces. The budget is crucial for ensuring national security and supporting military readiness. Governments typically review and adjust their defense budgets annually, considering factors like geopolitical threats and economic conditions. The budget can also influence international relations, as countries may increase or decrease spending based on their strategic priorities and alliances, such as those with NATO or the United Nations.