Explanation
Input sanitization is the process of validating and filtering the user input to prevent malicious code or commands from being executed on the web server or the web browser. Input sanitization can prevent this type of attack, which is called cross-site scripting (XSS), by removing or escaping any special characters or scripts that are not expected or allowed in the input field. Input sanitization can be implemented on the server-side or the client-side, or both, to enhance the security of the web application.
References
1: Web Application Attacks - N10-008 CompTIA Network+ : 3.2
2: CompTIA Network+ N10-008 Certification Study Guide, page 317
3: CompTIA Network+ N10-008 Exam Subnetting Quiz, question 15
4: CompTIA Network+ N10-008 Certification Practice Test, question 6