What does it do?
^^^^^^^^^^^^^^^^

Primarily it just provides the colorbox-javascript, so it's more a "library".

**What else?**

Clickenlarge mediafiles (images AND videos) with colorbox.

Group them into a popup by page or by a single record.

Translations of colorbox were transformed from javascript to XLF, and they are automatically added by TYPO3 with 'inlineLanguageLabelFiles' according to the configured language.