SPI Flash is a type of non-volatile memory chip that uses the Serial Peripheral Interface (SPI) protocol for communication. It retains stored data even when the device is powered off, making it ideal for firmware storage in embedded systems, routers, and IoT devices. SPI Flash is valued for its fast read speeds, low pin count, and compact size, which help reduce hardware complexity and cost. It is commonly used in cybersecurity contexts to securely store boot code, configuration data, and cryptographic keys, ensuring critical information remains intact and tamper-resistant.