A:Answer IPS is the panel type. You have various different type of panels, for example also VA and TN.
IPS allows more life-like and natural colors and great viewing angles. VA panels have higher contrast ratio's and TN panels are the fastest of them all with minimal response time but less color depth and poor viewing angles.
4k is ambiguous and may refer to 3840 x 2160 or 4096 x 2160, or potentially others. UHD (in this context) refers to 3840 x 2160 and nothing else. This resolution may be called 4k.
QHD =[Quad HD] refers to 2560 x 1440p pixels at a16x9 aspect ratio, four times that of 720p standard high definition and nothing else.
Ultra wide QHD boosts the horizontal pixels to 3440 for a 21x9 aspect ratio.
Ultra wide 21x9 is to much for gaming, 1440p is better