Originally Posted by onerikeronebridge
So you have root access but no ability to flash without s off?
Sent from my HTC VLE_U using XDA
Well you can flash with S-ON but it usually has to be done through ADB/fastboot on your computer. S-OFF gives you read right access to the devices NAND flash memory. It allows you to mount all partitions including /system in write mode while the OS is running. You can flash unsigned boots, HBoot images, permanently root your device, ect. You essentially have more control over your device. Gives you almost complete access to everything at any time.