namespace
A namespace is typically an alphanumeric string and some punctuation like a colon or period that specifies a named context, sometimes bound to a URL, for named things inside it; namespaces are often an antipattern in standards like vocabularies because they encourage everyone inventing their own terms to mean the same thing instead of discussing and interoperating. Namespace allow re-use of identical named things to mean different things in different contexts, which sometimes has downsides.
Criticisms
Over-Namespacing
It is possible to over namespace when you separate variables into a namespace for no real reason. See PuSH