Yours is faster than one, slower than the other, can go to 3 Gb of RAM not 4 (if you care) and has a bit slower video card (if you care) and maybe shorter battery life.
What does it mean? d*)(^ed if I know. Whether it makes any difference at all to you depends entirely on what you do with the machine.
Oh, and yours instantly dropped 10 - 20% in resale value this morning.
Anyway: Welcome to MR> Please make your thread titles descriptive of the question you are asking. Do you know how many hundred of threads have been created with that title? Wouldn't be a bad thing to read through the forum guides.