Name-space is an abstract group of elements. Within the group, element names must be unique, but elements of the same name can appear in different namespaces (so, in different groups). They are completely separate and in no relation to each other.

Generally speaking, the namespace indicator can be prefixed to the element name (such as xsl:stylesheet), given as a separate parameter (such as name="stylesheet" space="xsl"), or set in a separate call and later considered implicit.