blackrockmountain :
I am gonna get gtx 1060 6gb graphic card. My choice was i5-8400 with gtx 1060 6gb but my cousin told me that i7 is better
The i7 is better, but you wouldn't really notice a difference unless you're running a 144+Hz monitor and had a high end GPU, eg. GTX 1080 or better. If you're only targeting 60Hz and are only going to be using a midrange card like the GTX 1060, then the i7 is much less beneficial unless you're also going to be using productivity software that benefits from the i7's extra threads.