Playstation External Harddrive

[pablocsgobar]

Hi guys, my lil bro has a PS4 with 500gb and these days he can manage only 3-4 of the big games -
Im looking to help him for his birthday - can someone advise me if just getting a normal external will be best option or even possible?

Or is there a specific process of adding space to the PS4? What would be the best approach!

much appreciated - CarboKnights!
G