Why both i386 and X86_64

[Bob Chiodini]

I'm new to this list and the AMD 64 bit architecture and noticed during
today's update of hal and associated dependencies that both the i386 and
x86_64 RPMs were installed.  This does not seem to be the case for all
RPMs.  hald is ELF 64-bit, so I'll assume the correct one is running.

Why both RPMs?

>From yum:

Transaction Listing:
  Update: hal.i386 0:0.4.7-1.FC3
  Update: hal.x86_64 0:0.4.7-1.FC3
  Update: hal-devel.x86_64 0:0.4.7-1.FC3
  Update: hal-gnome.x86_64 0:0.4.7-1.FC3
Downloading Packages:
hal-0.4.7-1.FC3.i386.rpm  100% |=========================| 155 kB    00:15
hal-0.4.7-1.FC3.x86_64.rp 100% |=========================| 171 kB    00:11
hal-gnome-0.4.7-1.FC3.x86 100% |=========================|  78 kB    00:08
hal-devel-0.4.7-1.FC3.x86 100% |=========================|  98 kB    00:07
Running Transaction
Updating: hal 100 % done 1/8
warning: /etc/hal/device.d/50-fstab-sync.hal created as /etc/hal/device.d/50-fstab-sync.hal.rpmnew
Updating: hal 100 % done 2/8
Updating: hal-gnome 100 % done 3/8
Updating: hal-devel 100 % done 4/8
Completing update for hal  - 5/8
Completing update for hal  - 6/8
Completing update for hal-gnome  - 7/8
Completing update for hal-devel  - 8/8

Updated: hal.i386 0:0.4.7-1.FC3 hal.x86_64 0:0.4.7-1.FC3 hal-devel.x86_64 0:0.4.7-1.FC3 hal-gnome.x86_64 0:0.4.7-1.FC3
Complete!

Bob...