The Link module provides one or several fields for storing links. It supports additional link text titles and display settings.
Drupal 8: The Link module is a core module that only allows external links. Internal links can be added with the core module Entity Reference.
Drupal 7: The link module allows external and internal links. It does not allow adding links to a menu or navigation.
Installation: Link is part of Drupal core and can be enabled from the Extend page (admin/build/modules).
Input format: The Link module only allows external (i.e. absolute) links. Links can include anchors or query strings.
Validation: Links must include the web protocol (http:// or https://) in order to validate. Validation takes place after filling in the field. Other scheme names (e.g. ftp, git etc.) are not supported.
Link texts: Link texts (called "Link titles" in D7) can be added to each URL. Whether this is allowed or required can be set in the field management. Placeholder text can be added to appear in the fields before the user adds their own content.