What is a MOSFET driver, IGBT driver, IGBT gate drivers, MOSFET driver IC

 MIC4416 Series 18 V 3.5 Ohm SMT IttyBitty™ Low-Side MOSFET Driver - SOT-143-4

https://www.futureelectronics.com/p/semiconductors--analog--drivers--mosfet-igbt-drivers/mic4416ym4-tr-microchip-8061612