Pro Flash is a high-level firmware flashing mode within 3uTools designed for experienced users and technicians who need granular control over the iOS installation process. While the standard "Smart Flash" tool automates most decisions, Pro Flash allows for specific customization of how firmware components are sent to an iPhone, iPad, or iPod Touch.
According to guides from 3uTools, there are four primary modes available within the Pro Flash interface: pro flash 3utools