Firmware
Course: AP® Cybersecurity Shows up in: Unit 4: Securing Devices
Software stored on hardware that starts a device and controls it at a low level, such as the basic input/output system (BIOS) or Unified Extensible Firmware Interface (UEFI).
Appears in the course and exam description (CED): 4.1.C.3
Why it matters in Unit 4
Without a BIOS or UEFI password, an adversary with physical access can change firmware settings and boot the device from an external drive.
Example
A printer’s firmware is out of date and has a known vulnerability, so the fix is a firmware update.
Learn it properly, with a checkpoint 4.1 Device Vulnerabilities and AttacksGo deeper: the professional references
Security professionals worldwide use these: the NIST glossary (the U.S. government's official security dictionary), MITRE ATT&CK (real attacker techniques), MITRE CWE (software weaknesses) and the internet's own standards (RFCs). They go beyond the AP® course, so use the definition above for the exam.