This European term is French ("trail", "track") and synonymous with 'trail', 'slope', or 'groomed run' in North America. Pronunciation varies slightly in English, with British English using a long "e", (e.g. rhymes with "beast"), and American pronunciation using a short "i" (e.g. rhymes with "list").
Individual trails on pistes are graded by difficulty using ski trail ratings.
Pistes are usually maintained using tracked vehicles known as snowcats to compact or 'groom' the snow to even out trail conditions, remove moguls, and redistribute snow to extend the ski season. Natural snow is often augmented with snow making machines early in the season or when the snowpack is low.