Progressive House's roots are primarily in the U.K. in the beginning of the '90s, typified by producers like William Orbit, with his Guerilla label, and Leftfield, with their Hard Hands label. Two British DJs, Sasha & John Digweed helped popularize the sound in the club "Renaissance". The label Limbo Records launched from legendary Glasgow record store 23rd Precinct was also a major actor of the style. One of the biggest hits of the genre was "Passion" by Gat Decor.
Typical elements of the style are house rhythms around 125 BPM; a dubby, galloping/chugging bassline; and a dreamy, spacey atmosphere. In a sense, it is a combination of house and trance, with the soulful, booty-shaking elements toned down and replaced by long chords and dubby ear candy. It evolved into a more minimalistic aesthetic with the emergence of a new scene in 2003 led by musician/DJs such as James Holden & Nathan Fake from the label Border Community.
Related styles are Progressive Breaks, Progressive Trance, and Progressive Psytrance. It's often difficult to say a particular track is strictly progressive house, progressive breaks, or progressive trance, so people often lump the three genres together under a single "progressive" catch-all.