The procedure of modifying or replacing the contents of such
flash memory i.e ROM is known as flashing. Thus, in layman’s terms,
flashing is essentially the same as installing or modifying the
firmware of a device that is stored on its protected flash memory.
Such modification can be perfomed on a special partition of the system called recovery.
In Android, recovery refers to the dedicated, bootable partition that
has the recovery console installed
When you perform a factory reset, recovery is what boots up and erases the files and data. Likewise with updates — when restarting to install an official OS update, it's done in recovery. Recovery is also where one goes to manually install official OS updates downloaded from the Internet. (There are two types of recovery; stock recovery and custom recovery, but I'm not going to discuss it here)
Flashing is the term originally used to describe the "modifying or replacing the contents of ROM memory, and has been traditionally used to install fresh OS from custom ROMs, The term also embraces the operation of mounting various partitions in order to copy files to the SD card without having to remove it or reboot into Android as well as applications from a zip file through recovery, has now come to be associated with installing.
While most apps for Android devices are available at the app store for direct download and installation or as .apk files for direct installation, there are certain apps which are only available as zip files installable from recovery. Their installation procedure is the same as installing a custom ROM described.
Hence the reason, terms ‘installing’ and ‘flashing’ can be used interchangeably to mean the same thing .
- What Is Meant By Firmware, Stock & Custom ROMs And Flashing
- What is Android recovery?
- How To Install A ROM Or App From Zip File To Android Device From Recovery