What is Apple's iOS Rapid Security Response (RSR) and what class of vulnerabilities does it address faster than standard OS updates?

• A.A) Rapid Security Response (introduced iOS/iPadOS 16.4.1 (a)) allows Apple to deliver security patches to specific vulnerable components (WebKit, Foundation, kernel security hardening mitigations) without a full iOS version update, enabling deployment within days of a critical vulnerability discovery. It primarily addresses actively exploited zero-days targeting browser engines (WebKit) and system libraries where attackers have working exploits in the wild, where waiting for a full iOS point release would leave devices exposed for weeks.
• B.B) RSR delivers new iOS features in between major updates; it is primarily an experience improvement delivery mechanism, not security-focused.
• C.C) RSR provides security patches only to iCloud and Apple's server infrastructure; on-device components are not updated by RSR.