Scope
Content, modules, themes and emails
Beyond database content, the module also translates what shows up in the interface:
Modules
Interface strings of installed modules, translation file by translation file.
Theme
XLIFF translation domains of the active theme.
Emails
Core, module and theme mail templates, per language.
Two shortcuts round out the content screen: a floating widget to translate a piece of text on the fly, and a quick-translate window right on supported edit screens (product, category…) — both can be turned on or off from Configuration.