A/B Testing is a method used to compare two or more versions of a variable, such as a webpage, email, or security protocol, to determine which performs better. In cybersecurity, A/B Testing can be used to evaluate the effectiveness of different security awareness messages, authentication methods, or user interface designs in preventing phishing attacks or improving user compliance. By randomly assigning users to different groups and measuring outcomes, organizations can make data-driven decisions to enhance security measures and user experience.