Partitions are logical storage units made inside the device's persistent storage memory. Partitioning allows you to logically divide the available space into sections that can be accessed independently of each other.
The partition layout varies between vendors and versions. However, a few partitions are present in all the Android devices. The following sections explain some of the common partitions found in most of the Android devices.
This partition stores the phone's boot loader program. This program takes care of initializing the low-level hardware when the phone boots. Thus, it is responsible for booting the Android kernel and booting into other boot modes, such as the recovery mode, download mode, and so on.
As the name suggests, this partition has the information and files required for the phone to boot. It contains the kernel and RAM disk. So, without this partition, the phone cannot start its processes.