There is a difference between 'i.e.' and 'e.g.'

I'm in the computer lab at school typing up a document when, for the first time ever, I find myself in a situation where I need to use 'i.e.' or 'e.g.' I'm not really an 'i.e.' or 'e.g.' person which is mostly because I had no idea what the difference between them is and I do not want to use them wrong and look stupid.

But it was extremely appropriate to use them in this situation and there was no substitute. So I looked it up.

Both are abbreviations for Latin terms. According to quickanddirtytips.com, i.e stands for id est which means 'that is,' and e.g. stands for exempli gratia which means 'for example.'

You might be thinking to yourself that they mean pretty much the same thing and can probably be used interchangeably. No. There's a difference. Refer to the following trick from quickanddirtytips.com:

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.

E.g. is used to introduce examples and i.e. is used for further clarification.

FOR EXAMPLE:
I like sugary foods (e.g., cookies, pie and cake).
I hate almost all fruit with only a few exceptions (i.e., apples, bananas and watermelon).

My sugary foods list is not comprehensive, I like many more sugary foods in addition to cookies, pie and cake (examples). My fruit list is all inclusive. The only fruits I like are apples, bananas and watermelon (further clarification).

Also, AP style calls for a comma after the last period in both e.g. and i.e.

If you can't use them right, don't use them at all!