First person POV vs Narrative style writing

Hi guys. I was just thinking of the differences between the styles of writing and what can be achieved/conveyed by different writing styles. Mainly I'm focusing on the effects of a first person POV narration similar to how GRRM writes and comparing that to how a traditional bog-standard narrative perspective narration is written. I mainly am thinking of what can be conveyed in terms of ideas, thoughts and feelings of the character in the story while also delivering the plot for the reader. Thanks.