[TYPO3-dev] What's the difference between sys_language_content and sys_language_uid

[Simon Tuck]

Hi List,

Is there any significant difference between $GLOBALS['TSFE']->sys_language_content and $GLOBALS['TSFE']->sys_language_uid? I'm using 
sys_page->getRecordOverlay to get localized records and it appears to me that these properties are interchangeable and so I was wondering if 
there is any difference between them and if so, which property I should use...

Cheers
Simon