A statistical software package. Use this tag for any on-topic question that (a) involves Stata either as a critical part of the question or expected answer, & (b) is not just about how to use Stata.
Some other sources of Stata help:
'Stata' is an invented word, not an acronym, and therefore should not have all its letters capitalized (i.e. 'STATA' is considered incorrect). See the last item of the Statalist FAQ.