Kickstart Image → Specialized bootloader that initializes the hardware System Image → Contains the full NX-OS kernel and operating system Global configuration command mode → Provides access to the broadest range of commands that affect the device as a whole EXEC command mode → Allows for displaying device status and configuration information This knowledge is covered under Cisco IOS/NX-OS Software Basics in the FLDTEC training: Kickstart Image: A lightweight bootloader image that initializes hardware and launches the system image. It's comparable to ROMMON in traditional IOS devices. System Image: Includes the full NX-OS operating system, services, drivers, and kernel required to run the device. Global Configuration Mode: After entering privileged EXEC mode (enable), this mode allows changes to system-wide settings such as interfaces, routing protocols, and VLANs. EXEC Mode: Has two levels—User EXEC and Privileged EXEC. User EXEC provides limited diagnostic commands, while Privileged EXEC allows more extensive system views (show commands, reload, etc.). Understanding these layers is essential when maintaining or restoring NX-OS devices in field environments.