What is firmware and what happens when I update it?

What is firmware? In computing, firmware is software that is embedded in a hardware device. It is often provided on flash ROMs or as a binary image file that can be uploaded onto existing hardware by a user. Firmware is defined as: the computer program in a read-only memory (ROM) integrated circuit (a hardware part number or other configuration identifier is usually used to represent the software); the erasable programmable read-only memory (EPROM) chip, whose program may be modified by special external hardware, but not by [a general purpose] application program. Source: Federal Standard 1037C. the electrically erasable programmable read-only memory (EEPROM) chip, whose program may be modified by special electrical external hardware (not the usual optical light), but not by [a general purpose] application program. What happens when I update it? In practical terms, firmware updates can improve the performance and reliability, indeed even the basic available functionality of a device, and many devices benefit from regular firmware updates. One of the most common devices to have regular firmware updates are recording devices such as optical media writers (DVD, CD, Bluray), as media technologies extend, so firmware updates ensure hardware is kept up to date and compatible. Source: http://wiki.answers.com/Q/What_is_firmware

Updating a device's firmware can fix bugs and add new features.