Introduction to Android Partition

Android phones and tablets generally include the following partitions:

/boot
/system
/recovery
/data
/cache
/misc
/sdcard
/sd-ext
/boot

This partition can guarantee the normal startup of the mobile phone. It includes the kernel (virtual disk) and ram disk (virtual memory disk: a technology used to emulate a part of the memory (RAM) as a hard disk by software, which can greatly improve the performance on it. 

The speed of file access), if there is no such partition, the phone usually does not start normally. Only when necessary, the partition is formatted by the Recovery software.  
Once erased, the device can only reinstall a new boot partition. It can be implemented by installing a ROM containing the boot partition. Otherwise, Android cannot be started. .

/system
This partition is used to store system-related configurations other than kernel and ramdisk. It includes the user interface and software pre-installed on the phone. 
Erasing this partition will delete the entire system, but will not cause it to fail to start. You can install a new ROM (Android) by going to the Recovery program or the bootloader program.

/recovery
When the normal partition or kernel partition is destroyed and cannot be started normally, you can enter this partition for recovery. 

He is quite compatible with a simple OS or blos, which can be considered as a substitute for a boot partition, through which he can let us in this partition. For backup maintenance and recovery, we usually say that the flash machine refers to this partition.

/data
This partition contains the user's data information, such as: contacts, SMS, settings, user-installed programs, erase this partition, equivalent to the phone to restore the factory settings, you can select "data / factory reset" in the Recovery mode This partition.

/cache
This partition is the Android system cache, which holds the most frequently accessed data and applications. Erasing this partition will not affect the personal data, just delete the cached content already saved in this partition, and the cached content will be automatically generated again during the subsequent use of the mobile phone.

/misc
This partition contains settings related to some system settings and system feature enable disables. These settings include CID (operator or zone ID), USB settings, some hardware settings, and more. 
This is a very important partition. If this partition is damaged or some data is lost, some specific functions of the phone may not work properly.

/sdcard
This partition is internal storage and can store photos, videos, documents, ROM installation packages, etc. It is completely safe to erase this partition.