1. A specific class of software encoded directly into a hardware device that controls its defined functions and provides the low-level control for the computer’s specific hardware (such as the firmware that initially boots an operating system).

Source: Election Terminology Glossary - Draft, National Institute of Standards and Technology (NIST),

2. Computer instructions that are encoded directly into computer hardware. Firmware is resident to the hardware and cannot be altered without modifying the hardware. Voting systems may contain firmware that cannot be altered without replacing the hardware.

Source: Information Technology Terminology, U.S. Election Assistance Commission,

3. Software loaded into a sort of computer memory that cannot be easily changed, called “read only” memory, as opposed to “read/write” memory, which is more easily changed. Computers use firmware to execute basic functionality like starting up.

Source: Voter Protection Project, Verified Voting, Electronic Frontier Foundation,

4. Software programmed into read-only memory (ROM).

Source: U.S. Cyberspace Solarium Commission, March 2020,