Fastboot (fast loading) is a programming mode in Android smartphones that allows you to perform various manipulations with the software when standard methods and solutions are useless. By its principle and purpose, it is closest to Recovery, but, unlike its usual counterpart, it is located in a more reliable and safe place. Fastboot is a protocol that can be used to re-flash partitions on your device (update the flash file system in Android devices). It is this small tool that comes with the Android SDK (Software Developer Kit), which is an alternative to the Recovery Mode for doing installations and updates. Not all phones have a fastboot mode that the user can.