Update docs/glossary.md

Co-authored-by: Steve Piercy <[email protected]>

Author: lord2anil

docs/glossary.md

@@ -643,6 +643,7 @@ Content Delivery Network
 CDN
     A Content Delivery Network (CDN) is a network of servers located in various geographic regions that work together to deliver web content to users quickly and efficiently.
 
+unique identifier
 UID
    UID is an abbreviation meaning "User Identifier." On a Unix-like operating system, it is a unique numerical identifier assigned to each user. The system uses the UID to identify the user and determine access permissions to files, directories, and other system resources.