Confuion about instrument and line in inputs (and were should a guitar be plugged into)

Hi, let's say i have an interface with one instrument level input and one line in level input. A guitar should probably be plugged into instrument input (right?) but should the guitar be run through a d.i. box first or not? On the other side can a guitar be plugged directly into a line in input and what effect would that cause?
Last edited by johnmanthop at Jun 21, 2017,