vacation是假期的的意思,那么他的介词搭配 on vacation与for vacation有什么区别么?

on vacation
在度假中；在假期
Want to volunteer on vacation?
想要在假期做志愿者吗?
They are on vacation this week.
他们这星期都在休假.
for vacation
度假
They are gone for vacation.
他们度假去了.
I went toThailand for vacation.
我是去泰国度的假