Updated the Namespace definition

source/glossary/index.html.md

@@ -290,7 +290,12 @@ A relational database. Currently only supported if you are using EE. It is owned
 ### Namespace
-*** Needs definition here
+In computing, a namespace is a set of symbols that are used to organize objects of various kinds, so that these objects may be referred to by name.
+
+Prominent examples include: 
+- file systems are namespaces that assign names to files; 
+- programming languages organize their variables and subroutines in namespaces; 
+- computer networks and distributed systems assign names to resources, such as computers, printers, websites, (remote) files, etc.
 ### Nginx