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

• 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.RSR is Apple's channel for delivering features between major releases (Live Text improvements arrived this way in the 16.x line), and the security content of an RSR is limited to configuration data, with code fixes reserved for the point release. Enterprises treat it like an optional update. The class of problem it addresses is a broken heuristic rather than an exploited defect.