Knowledge Management is the process that allows users to create, categorize, review, approve and browse important information in a centralized location that is shared by the entire organization1. Knowledge Management helps users to find relevant and accurate information quickly, reduce the need to rediscover knowledge, and improve the quality of service and customer satisfaction1.
References
* Knowledge Management - ServiceNow1

Explanation
The System Administration > Normal Security module is the recommended way to return to normal admin security levels after finishing your work on High Security Settings. This module will automatically disable all high security settings and restore your permissions to their original state.
References:
ServiceNow Product Documentation: High Security Settings
- https://docs.servicenow.com/bundle/vancouver-platform-security/page/administer/security/reference/high ServiceNow Community: How to disable High Security Settings
- https://www.servicenow.com/community/now-platform-forum/platform-security-everything-you-need-to