Translation module - can't find it after upgrade

Hello guys,

I've just upgraded a legacy site, and am trying to upgrade some translation modules which appear to function with Drupal 7... however, they require a module called Translation which I can't seem to find in my list of core Drupal modules or on the Drupal.org website.

This is probably a stupid question, but where do I find it?

Thanks in advance,

~Calon