An FPGA board is a development board built around a field-programmable gate array, usually with memory, power regulation, connectors, and debug interfaces for prototyping. Unlike a fixed-function chip, an FPGA can be reconfigured after manufacturing to implement custom digital logic, from simple controllers to high-speed packet processing.
In cyber security, FPGA boards matter because they let defenders and attackers build specialized hardware behavior that software alone cannot match. They are used for hardware testing, protocol analysis, and security research, but also for stealthy or hard-to-inspect payloads, fast brute-force logic, or emulation of peripherals and devices. Security teams should treat bitstreams, build files, and device firmware as sensitive artifacts, because weak change control or unsigned configuration can turn reconfigurable hardware into an attack surface.