The rationale is that the first one will support 64 bit systems running 10.6 and higher, the second 32 bit Intel running 10.4 or 10.5, and the last one PPC systems running 10.4 or 10.5.
The rationale is that the first one will support 64 bit systems running 10.6 and higher, the second 32 bit Intel running 10.4 or 10.5, and the last one PPC systems running 10.4 or 10.5.