刚才在写paper时突然脑子眩晕，搞不清i.e和e.g到底有什么区别了，感觉都是“例如”的意思。e.g.没有问题，肯定是例如了。但i.e.呢？不敢含糊，Google了一下，bingo! I came across with this post.
I.e. and e.g. are both abbreviations for Latin terms. I.e. stands for id est and means roughly “that is.” E.g. stands for exempli gratia, which means “for example.” “Great. Latin,” you’re probably thinking. “How am I supposed to remember that?”
But by now, I’m sure you know that I’m not going to ask you to remember Latin. I’m going to give you a memory trick! So here’s how I remember the difference. Forget about i.e. standing for “that is” or whatever it really means in Latin. From now on, i.e., which starts with i, means “in other words,” and e.g., which starts with e, means “for example.” I = in other words. E= example.