Nikto is a web server scanner that is designed to identify potentially exploitable vulnerabilities within web applications. It checks for thousands of common issues, outdated versions, and specific problems on various types of servers. The correct answer specifically highlights that it is a web server scanner, which is its primary function. Other options do not accurately represent Nikto's main purpose; 'Creating secure code' describes an activity related to secure SDLC, not Nikto's functionality, 'Decrypting SSL traffic' is something more relevant to an intercepting proxy or similar tool, and 'Analyzing network traffic' is too broad and not specific to web server vulnerabilities.