Controlling what software is allowed to run—and isolating it when needed—is a fundamental principle of endpoint security. In this episode, we examine application allow lists, which explicitly define which executables, scripts, and libraries are permitted to run in a given environment. This contrasts with traditional antivirus, which blocks only known threats—allow lists stop anything that’s not pre-approved, providing a much tighter security model. We also explore isolation techniques like sandboxing and containerization, which prevent even approved or suspicious software from accessing system-level resources or moving laterally if exploited. Used together, these techniques significantly reduce the likelihood of malware execution, privilege escalation, or unauthorized network access. Implementation requires thoughtful policy design, compatibility testing, and tuning—but the payoff is a hardened environment that resists many of the most common endpoint attacks.