Ez track numbering

[Jeff1980]

I used the Anyrail computer program to create my layout. This program lists the nomenclature for each piece of track, but I am finding the actual tracks have added numbers at the end. Fir example, the 22" curve is a Hh4403, but I am finding some are H4403A4-1, some are H4403A-2 and so on. Are the all the same? What are the differences?