It's a very common and versatile word that can refer to:
* Employment: "I have a new job." (我有一份新工作。)
* Tasks: "This work is very difficult." (这项工作很难。)
* Labor: "The workers are busy." (工人们很忙。)
It's important to note that "gong zuo" is a general term for work and can be used in many different contexts.