What is a namespace?

In the context of Linked Data, a namespace helps records have unique names. A namespace is a component of the URI. In a group of URIs produced as part of a dataset the shared part of the URI is often the namespace. For example all concepts of the Language of Bindings thesaurus start with "https://w3id.org/lob/" which is the namespace for the thesaurus. In Linked Data the namespace may be declared with a shortcut using the keyword prefix. For example: @prefix lob: <https://w3id.org/lob/>. The prefix lob can then be used instead of the full namespace.