The terminal operating system version compatible with the second-generation iPad is iOS 9.3.5 (or 9.3.6 for some models). This represents the final software iteration made available for this particular hardware, marking the end of official software support by the manufacturer.
Understanding this limitation is crucial for users of these devices. While the operating system provided a functional user experience at the time of its release, modern applications and web technologies often require more recent system architecture. The inability to update beyond this version restricts access to newer features, functionalities, and security updates present in subsequent iOS versions.