A street bike is pretty much anything that's street legal.
A sport bike is a bike that is designed for spirited riding and this is a very wide range. Most anything that isn't a cruiser is very sporting in nature.
A standard is a bike that's with no or little fairing and with a comfortable seating position with straight back and footpegs pretty much underneath the body.
A naked bike is just another name for standard. Some used the term naked/street fighter to denote a bike that is like a standard bike but more aggressive in nature like the Aprilia Tuono, the KTM SuperDuke, the Triumph Speed Triple, the Monster S4R, S2R 1000, Kawi ZRX. Think of bikes that are mean and not necessarily powerful because the SV1000S, ZR7S and the Z1000 are powerful bikes but they aren't really "mean".
Supersport denotes the 600-cc crotch rockets: CBR-RR, R6, GSXR600, Ducati 749, Gixxer750, etc. Sporty bikes with fairings like Katana or Ninja 650R aren't supersports.
Superbike denotes the 1000-cc crotch rockets: once again, the Japanese Liter bikes, Aprilia RSV Mille, Ducati 999, etc.
Touring: big ass couches like Goldwing, Electraglide, K1200LT, R1200RT.
Sport Touring: Touring bikes with lesser luxuries than the above. Also lighter, faster and sportier. Think Triumph ST, Ducati ST3, ST4, BMW R1200ST, Kawi Concour, ZX1400, Honda VFR, ST1300, Yamaha FJR-series, Hayabusa.
Motards are dirt bikes with revised suspensions and street slicks.
Supermotards are bigger motards.