This article explains how to choose between i.e. and e.g.
Not quite sure when to use these or how they're different? Well, i.e. is Latin for id est and means that is or in other words.
Here are some sample sentences:
The standard discount applies; i.e. 10%.
Our backup drives (i.e. drives F and G) are new.
e.g. is Latin for exempli gratia and means for example. Here are some sample sentences:
Try using easy-to-read fonts; e.g. Georgia and Verdana.
Some staff (e.g. John and Tony) are on leave.
Users of American English frequently put a comma after i.e. and e.g.:
The standard discount applies; i.e., 10%.
Some staff (e.g., John and Tony) are on leave.
This comma is usually ommitted by users of British English.
Note that it is not necessary to set these abbreviations in italics in normal use.