Documentation for JIRA 4.3. Documentation for other versions of JIRA is available too.
The Labels page for a project in JIRA shows labelled issues in a project.
To browse a project's labelled issues,
Screenshot: 'Popular Labels' view for a Project
Screenshot: 'All Labels' view for a Project
Next to the word 'Field', the name 'Labels' will be shown — this represents any labels that have been applied to your issues as described in Labelling an Issue (hidden draft for 4.2). If any other names are shown, you can click them to see any other Labels custom fields in your JIRA system. For example, the screenshot above contains a Labels custom field called 'Epic/Theme'.