LED = LCD display with LED backlighting. LED's are smaller and also have the potential to make the screen brighter.
So the different forms you've typed, LED backlit LCD, backlight LED, they're all the same thing
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