Yes wen you bore you increace the size of thr hole that the piston is in, also you have to get bigger pistons. To port you make the holes in the cylender (the ports) larger and diffrent shapes, It depends on what kinda power you want to make. Polishing is not needed on the intake and some times a ruff port can help (I have no clue why but it dos). a bore will not gane you power but a port job will be night and day.
Chevshee