查字典：contractor

con·trac·tor

 a person who contracts to furnish supplies or perform work at a certain price or rate.

 

就是說：

 a person who contracts to furnish supplies 或者  a person who contracts to perform work

 

關鍵詞是contracts, 不是perform work

 

contractor 特指 one who enters into a contract to provide work, services, or goods

 

承包商 vs 合同工 = 老板 vs 打工仔