[Q] after unlocking bootloader, do i have to install original firmware topic

dear members,

i m using xperia m c1904 - andorid 4.3
í m new at unlocking bootloader. but i just learned it from your post that how i can unlock bootloader.
but i still want to know that after unlocking bootloader , do i have to install sony 4.3 operating system?

please help me.