part time job 是 “小时工/钟点工” ，temporary and short and can depend on your personal timetable. 打工 is more like "to work", while that kind of word is usually based on "muscular labor". But that's not absolute. For example, you can say “我就是一个打工的”，which means you create the wealth that largely belongs to "you boss".

打工和时间没有任何的关系，和打工对应的是老板之类，只要你的工作不是为了自己花钱开办的公司、企业、店面等等，你为其他老板工作，都叫打工。打工就是工作，就他人工作，不是为自己工作。和是不是part time没有关系。

1) part time job. 2) full time and basic job. For example, Tom is a developer, he works in Microsoft and he is well paid. But he can still say that 他给微软打工－－－ because he is just a developer, instead of an engineer. In this case, in fact it's a kind of self-mockery. Tom just wants to express that his job is basic, whereas his goal is to become an engineer.

It means a job which you are undertaking for someone else. And you are the employee. It can be part time or full time. Part time jobs are mostly 打工.

yes, it means part time