Forgive me, Camaro Lords for I know not what I say...

LS Series is engines i.e LS1 LS2 LS3 LS4 LS6 LS7 and LS9.
LS1's- 5.7L 346 CI 345 HP engines in base corvettes from 1997-2004 and Camaro SS'S and Z28's from 1998-2002, and GTO's in 2004.

LS2's- 6.0L 362 CI (cubic inch) 400 HP engines in base vettes from 2005 up and in the 2005 & 6 GTO's

LS3's- New engines in the 08 vettes and quite probably one version ov V8 Camaro.

LS4's- 5.3L engine in traverse engined (front wheel drive sideways mounted engine) V8 Cars such as the new Impala SS.

LS6's- 346 CI 5.7 basically an LS1 with stronger block, bigger cam, better heads and intake with 405 HP. Came in the C5 Corvette Z06's.

LS7's- 427 CI complete race bred 500 HP engine in the new C6 Z06's

LS9's are the new supercharged 6.3L engines from GM ranging from 600 (in the new CTS-V cadillac) to over 650 HP in the new Super Vette whatever they call it.

SS, And Z28 are option packages on GM vehicles with the Z28 being exclusive to Camaros only. Too much to explain here but most all these cars had bigger engines than the base cars where now days They just mean the get a V8 over the base 6 cylinder.

C5 C6 etc are models of Corvettes the first Corvette was a C1 the current is a C6 that number changed every time they body changed.

Fbody is the chassis nomenclature for Camaros/Firebirds and they have a similar "generation" based on bodystyles. Gen 1's are the first 67-69, Gen 2's are the next body style a la smoky and the bandit Firebird was a 2nd Gen. The 3rd gen are the more sleek looking firebirds and T/A's (Trans Am's =V8 in the Firebird model line) and old IROC Camaro's which most people know them by. And lastly was the 4th Gens which were the more pointed narrower front ended cars from 94-up to 2002.

Thats a small glimpse of the GM world of nomenclature. sitck around read more and you'll hear much more.