This can allow you to flash the stock ROM for unbricking the device or upgrading the software on it. So, you would need to install the MediaTek USB VCOM drivers (or MediaTek Preloader Drivers) on your PC to be able to flash firmware files on any MTK Android device using the SP Flash Tool. The figure below explains how the Preloader on MediaTek-powered Android devices can communicate with the SP flash tool over USB (Courtesy of mcgrady_tracy at CSDN). Something very identical to the EDL mode on Qualcomm Android devices. Apart from being responsible for the boot process, the Preloader on MediaTek devices can also act as an interface to download/flash firmware files to the NAND memory of the device, which is where the Android OS resides. When it comes down to MTK Android devices, this is called the “Preloader”, a proprietary loader developed by MediaTek.
All Android devices come with a bootloader that executes the kernel and defines how the Android system is booted (known as the “Boot Process”).