Namespace

A namespace is a context in which its names are unique. Namespaces can be hierarchical. In that case, the names are unique within each hierarchical level. Examples:

• Soccer: The team is the namespace. The jersey number is the unique identifier.
• Telephony: A namespace is, for example, the area code; the phone number is the unique name within that namespace.
• Domain Name System (DNS): A namespace is, for example, a second-level domain. In that case, hostnames (www) and subdomain names (dev) are unique.
• URIs (Uniform Resource Identifiers): Each URI can be regarded as a name with the parent resource as its namespace.