I know this is " Guitar Gear " but found no " others " tab ,so asking here.

Basically i have a Samsung S5 phone camera, and it's capable of " 1920x1080p " , but it's still not crystal clear, not like what i'd watch on a perfect 1080p video, why is that? Basically i was interested in a Go Pro Hero3+ Black, and it's also 1080p capable, why is the 1080p video for the gopro better than my 1080p on my phone ( Or is it not better ) ?
You didn't find a section for that 'cause this is ultimate guitar, not ultimate photography.

Resolution is one of the info that tell you how much data can stay in a single frame.
It means how much different points of different colors can be contained in a single frame.

How good the image will look though depends on a shit ton of factors, mostly light and then sensor quality, and being phone sensors' about as big as a pin's tip, it'll give you a hell of a noisy image.

Taking a picture under good light condition will not be THAT bad, but making a video in shady environments will not be good looking with whatever phone.