their life与their lives有区别吗?

their life与their lives有区别吗?
那their life里的life是很多人共有的生活还是他们各自的生活或者要看具体语境判断？
如果要说救了他们的命呢？是save their lives吗？那这个又怎么解释？

Lives是life的复数形式,如果你说their lives的话就是强调他们每人有不同的生活,如果不是特别强调的话用life就好了
留学时老外说的~
注：life当生活用时可数,引用牛津字典的原文：
Many of these children have led very sheltered lives (= they have not had many different experiences).
但作为生命时不可数,以下为牛津字典原文：
[Uncountable] the ability to breathe,grow,reproduce,etc.which people,animals and plants have before they die and which objects do not have:life and death The body was cold and showed no signs of life.My father died last year—I wish I could bring him back to life.In spring the countryside bursts into life.
国内是有教“生活不可数,生命可数”之类的,但life的用法并不这么单一,楼上有人争论这个,那我就引用Yahoo Answers里老外的原话来解释："Lives" is used when speaking of more than one life.
So if you are speaking of multiple people each having a separate life,then you would use "lives".Such as "Days of Our Lives".
If you are speaking of one person but of the different personas they wear in their existence,then you would use "lives".Such as a person might have a personal life and a professional life,so you would be speaking of that person's lives.
If you are speaking of a group of people sharing the same experiences living as a group,then you would use "life".Such as "Our life at camp",because it refers to a group of campers and a group is a singular unit.
也就是我说的：如果你说their lives的话就是强调他们每人有不同的生活,如果不是特别强调的话用life就好了
生命不可数,见上文牛津