Term Kind Topic What it is
Content Security Policy protocol Frontend Security A response header declaring which sources of script, style and other resources the browser may load, which turns a script injection from a compromise into a blocked request.
Frontend Security Boundary concept Frontend Security The rule that nothing enforced in the browser is a security control, and the browser-side mechanisms that reduce blast radius anyway.
Origin Isolation Sandbox Origin, User Content Origin practice Frontend Security Serving user-uploaded or untrusted content from a separate origin, so that content executing there has no access to the application's session, storage or DOM.
Third-Party Script Governance Page as an Execution Environment, Vendor Script Review practice Frontend Security Reviewing and constraining what executes on a page, because every third-party script runs with the page's full privileges - and each one is added individually while the aggregate determines the security posture.