leader 指国家、民族、政党、组织等的领导或领袖。强调领导能力、含有能够引导、指导、控制被领导者并获得其支持的'意味。
boss 非正式用词，多作口语用，可指任何负责人，也可指经理、老板或工头。
例句：
1. The boss retains enormous influence by reason of his position.
老板由于自身的地位而一直有极大的影响力。
2. As the boss began to rant, I stood up and went out.
老板开始咆哮的时候，我起身走了出去。
3. He seemed to be in direct contact with the Boss.
他似乎直接和老板联系。
4. As long as I deliver the goods, my boss is very happy.
只要我做好本职工作，我的老板就很高兴。
5. The boss covers all bases when he sets up a job.
老板设立一个工作岗位时，需要方方面面都考虑到。