Your image is just a data file, or a collection of zeroes and ones called BITS (BInary digiTS) of information stored in a computer memory. For a modern digital SLR camera shooting a 20Megapixel (20M) image there can be 240 million bits in a single image. Bits are arranged into 8 bit words called Bytes (B). Each image is therefore 30 Megabytes (30MB) in size.
Take 800 images (easily) a day at a wedding and you can see that your image storage requirements are going to grow rapidly.
In the film world if a silverfish or mouse nibbled at the corner of a photo it may still be readable, but in the digital file any corruptions and the whole image is possibly unreadable. You need to have reliable computer equipment and reliable storage of your files.
I use Apple Mac equipment. Others argue that PCs are just as good or better but they are mistaken. Having used PCs and Apple side by side for over twenty years I believe I can speak with experience. Most professional photographers I have seen are using Macs, so that tends to support the argument.
The Apple OSX operating system supports Raw files natively. You can open a Raw image file directly in operating system. Windows requires additional software to supply the necessary decoders and that can result in inconsistent quality. Hasselblad do not offer the same support for other cameras on its Phocus 2.5 software for the Windows platform as it does for Mac OS for this reason.
The Apple Mac is based on the Unix operating system, probably the most reliable system commercially available. It comes with built in automatic backup in the form of TimeMachine and it has FireWire 800Mb/S data transfer to peripherals.
It is also easy to connect with servers and the server licences do not have client fees. Operating systems and upgrades are comparatively cheap. The last upgrade from OS 10.5 to OS 10.6 cost $39 retail in a box, and you get the full version, not “Home” versions. Compare that to Windows 7 for around $400.
Cool stuff is the integration with wireless networking through Apple Air Port Wifi and other products. The display options for not just photos but movies and music through iPhone, iPad and Apple TV are all excellent.
MORAL 4. Get a Mac. It just works.