Learn in the textbookFundamental Concepts of IoT and Embedded Systems
DefinitionFirmware (ファームウェア) is software written into a device's internal memory that serves as the foundation, directly driving the hardware parts.
ExplanationIt is the first thing to start when the power comes on, and it controls parts such as buttons, motors and displays. Software running in an embedded system is called embedded software, and firmware is the part of it that handles the groundwork of controlling those parts. It usually sits in rewritable flash memory, so it can later be updated to fix defects or add functions.
AnalogyThink of it as a set of operating instructions written inside an appliance: you never see it, but swap in new instructions and the same machine behaves differently.
Memory hookFirm sits between hard and soft: firmware is software on the harder end, between hardware and software.