CCS/TMS570LS3137: What are differences between fill= and vfill= in the .CMD file

Tool/software: Code Composer Studio

What are differences between fill=0xABCDABCD and vfill=0xABCDABCD

MEMORY
{
VECTORS (X) : origin=0x00000000 length=0x00000020 vfill=0xABCDABCD
FLASH_API (RX) : origin=0x00000020 length=0x000014E0 vfill=0xABCDABCD
FLASH0 (RX) : origin=0x00001500 length=0x00021000 vfill=0xABCDABCD

SRAM (RW) : origin=0x08002000 length=0x0002D000 vfill=0xABCDABCD
STACK (RW) : origin=0x08000000 length=0x00002000 vfill=0xABCDABCD
}

MEMORY
{
VECTORS (X) : origin=0x00000000 length=0x00000020 fill=0xABCDABCD
FLASH_API (RX) : origin=0x00000020 length=0x000014E0 fill=0xABCDABCD
FLASH0 (RX) : origin=0x00001500 length=0x00021000 fill=0xABCDABCD

SRAM (RW) : origin=0x08002000 length=0x0002D000 fill=0xABCDABCD
STACK (RW) : origin=0x08000000 length=0x00002000 fill=0xABCDABCD
}