Distinct from
洗烘套装 (xǐhōng tàozhuāng, a stacked separate washer + dryer pair).
一体机 means 'all-in-one machine'—you can also see
打印一体机 (printer/scanner combo). In China, balcony-installed laundry is the norm, so the compact one-unit format is popular despite slower drying than dedicated dryers.