K and N Filter vs Intake System

Hi, I am kinda new to modding and would like to know what to expect between just putting in a performance filter like a k and n and putting in a complete intake system like a APR carbonio?

TIA

K&N drop in is simple but only does a little for you (i have one in my rav4 and had one in my matrix)

full cold air or short ram intake make more of a difference and sounds good too! i think ima go full intake one day...