Trigger "creep" is any actual movement of the trigger after it engages the sear before the release is felt.
It's a function of the thickness of the "notch" in which the two interlock.
The only things you can really do to change it is to smooth it out with honing and polishing or it can be reduced by filing away some of that thickness.
It's there as a safety feature to help prevent accidental release of the trigger.
Some fully adjustable triggers can be set to minimize that distance and generally have smoother engagement surfaces so the trigger operates and breaks more cleanly than the factory trigger but, don't over do it or you're going to end up with an unsafe trigger.
I know lots of us like to "do it ourselves" here but unless you really know what you're doing you're always going to be best off by letting a qualified, competent gunsmith do your trigger work or replacements for you.