The process when
additional data is written (burnt) out to optical disc, so they can played
everywhere, however, you cannot edit any data inside the disc, let alone erasing the whole disc (CD±RW, DVD±RW, DVD±RAM, and BDRE are the
exceptions, because DVD±RAM cannot be finalized, while RW-disc and BDRE can be erased, though you cannot edit the data after you finalize it---so you need to erase the whole disc and repeat the burning process if there's any mistakes)
This process also known as "Closing"