I am not aware of that use of the term "modulation." I call that "transposing."
If you are in the key of C, then if you transpose up to keys, it would be E. One key would be D. If you transpose it down one key it would be B. If you transpose it down two keys, it would A.
Remember that if you are using the major scale, you have a step pattern of whole, whole, half, whole, whole, whole, half. So if you are using the major scale and transpose up one key, it would be one step (capo two frets higher when using the same chord shapes). If you transpose up two keys, it would be two steps (capo four frets higher when using the same chord shapes). But if you transpose up three keys, it would require putting a capo FIVE frets higher when using the same chord shapes.
I hope that did not serve to confuse you.
Modulation, as I understand it, has to do with vibration reproduction out of speakers. Or, it has to do with the width a string vibrates. Neither of those meanings relates to the question I understood you to be asking, but it is possible (likely even) that someone, somewhere uses modulation to mean transpose.
This may be a good topic to move to the Theory forum.