Question: What the heck is the difference between house, progressive house, tech house, and deep house, etc? Answer: Most these styles or house became commonplace in late late 80s and early to mid 90s... But you could say roots started even before the 80s if you wanted to push the envelope of claiming Dub and Disco were it's roots.
Simple explanation: Different variations of 120-130 bpm music (4-on-the-floor).
Little more in detail...
House: 120-130 BPM (beats per minute, the tempo of the song) with a 4 on the Floor beat (kick hat snare hat kick hat snare hat).
Chicago House: the original "house music." Sped up disco breaks, simple synth lines, and R&B a capellas over the groove. The beat rarely stops. Usually around 125 bpm
Techno: Detroit version of Chicago house. More influence from R&B than disco with funky synth bass licks, drum machine loops, and rap or R&B a capellas over the groove. Groovier and darker than Chicago house. Slower and around 120 bpm.
Tech-House: crossover of techno and house. Same Chicago style loops and vocals but with Detroit style basslines and percussion. Quicker than both but it has range between 125-128 bpm
Progressive house: faster at 128 bpm, and unlike the grooves of the other genres it's influenced by trance with a focus on melodies and chords with long builds and bridges where the beat drops out. Nowadays it's a catch all for mainroom house, but I'll get to that in a second.
Deep house: slower, around 120-123 bpm with a characteristic bass pluck sound. Techno influence is pretty easy to hear, but to me it sounds like more modern techno. Pitched down vocals, psychedelic soundscapes, and groovy basslines are the style of deep house.
Minimal: sometimes also called Berlin House or Berlin Techno, this is the more European response to the American styles of house. Focus on simple, repetitive basslines and the addition of elements over time to build up a groove from nothing and then break it all back down.
Electro house: focus on the bassline, but with more complex sounds than other genres. In electro house the bassline is the entire focus. It started with electro and ended up nowadays with complextro with those sporadic, heavy and aggressive basslines.
Mainroom house: somewhere between electro house and progressive house this genre popped up. It's what's played in the "mainroom" of the club, this is the easily digestible and formulaic tracks. More or less the "pop" of house music.
Festival house/Festival electro: kind of the mainroom of electro, this is the build build build, chords, drop with one synth playing one rhythm with a heavy kick. You hear it in festivals, hence the name.
A good dig in the subject can be found here with a nice sample of music styles... Nice visual diagram.
http://techno.org/electronic-music-guide/