People often confuse these two abbreviations.
e.g. means “for example”. (It comes from the Latin exempli gratia “for the sake of an example”.)
- Some foods are good for us to eat (e.g. fruit, fish, vegetables). Other foods are bad, or should be eaten in moderation (e.g. fatty foods, foods with additives, sugary foods).
i.e. means “that is”. (It comes from the Latin id est “that is”.)
- Not surprisingly, the closest planet to the sun (i.e. Mercury) has the most extreme temperature variations in the solar system.
When we use e.g. we simply offer some examples or suggestions among many. When we use i.e. we say exactly what we are talking about.
Note that you will often see them written without full stops or periods, thus: eg and ie
Also note that “that is to say” means the same as “that is”.