What is the difference between aboot and boot? I'm looking through my device and I noticed within /dev/block/platform/msm_sdcc.1/by-name that there is boot and aboot partitions. What is the difference between them? Mainly what is aboot?
The Application Bootloader ABOOT boots the Android kernel/Recovery kernel. 

It is the mechanism to download images onto the device from a host machine (like Windows/Linux PC).

On Samsung devices it runs the ODIN protocol on the device.

The Primary Bootloader boot part is a computer program that loads the main operating system or runtime environment for the computer after completion of the self-tests.

The PBL acts as a communication engine to download the Secondary Boot Loader (SBL) into the internal RAM and then activates it.

The SBL adds functions for erase and programming of flash memory and EEPROM; it also handles the actual download of new or updated software. This allows a minimum ROM utilization by the PBL