What is the difference between the toner cartridge and the drum unit?

Can I use non-Brother or third party supplies with the Brother machine?

I just replaced the toner cartridge and the LCD continues to display the message "Toner Life End" or "Replace Toner".

I still receive the error message "Replace Drums", "Replace Drum(X)", "Drum End Soon", or "Drum End Soon(X)" after I replace the drum unit with a new one.

Replace the drum unit. (With Video Instructions)

Replace the drum unit.

I don't think I got the full yield from my high-yield toner cartridge but the message "Toner Life End" or "Replace Toner" is displayed on the machine or the LED is on or flashing.

I print mainly black and white documents. How can I stop the life of my color toner cartridges from decreasing when I print?

How do I replace the Belt Unit? (With Video Instructions)

How do I replace the Waste toner box? (With Video Instructions)

How do I replace the Belt Unit?

How do I replace the Waste toner box?

Can I buy any MICR toner?

What are the expected yields of the consumables?