What is an LED driver, LED power supply, led light power supply, Lighting

 STP16CPC26 Series 90mA 30MHz 16-Bit Constant Current LED Sink Driver -TSSOP-24EP

https://www.futureelectronics.com/p/semiconductors--analog--drivers--led-drivers-linear-mode/stp16cpc26xtr-stmicroelectronics-3018365