1.c4 c5 - Symmetric English, leads to positional play. Black simply copies White's moves. Ultimately, one player or the other must take a risk and break the symmetry if they want to win, often with d4 or d5 but sometimes other ways. Sometimes neither player breaks the symmetry and a draw is agreed to.
1.c4 e5 - This line leads to active, tactical play. Typically both sides bring out their knights (2.Nc3 Nf6 3.Nf3 Nc6... Four Knights variation) and then either 4.e3 or 4.g3 followed by 4...Bb4 and then the fireworks begin. Warning! If you attempt to attack before bringing out both your knights you are likely to fall into a trap unless you spend some time preparing your variation.
I plan to play someone who plays the English in every game as white. I would like to know the ins and outs of the opening, traps to look for and sound black counters.