Everything on here is a free softmod (software modification), meaning you don't have to buy anything or deal with any hardware.
Even better than that, we also take the time to explain what you are doing and why, so you're not blindly hacking away.
Although it may be a little unnerving to simply let an application do so much at once, most users report no difficulty with the massive updating effort, although the tool will also permit individual updates instead of a larger mass-update operation.
But sometimes system updates contain updates for individual channels, and in some cases, as with the Shopping Channel, you cannot use that channel without the update. If you are running the final Wii OS version 4.3, then you probably shouldn't have to worry about system updates adversely affecting your Wii.
If you're running something earlier, though, you'll need to update your platform.
When the software is run, the IOS that is hardcoded gets loaded by the Wii, which then loads the software itself.
If that IOS does not exist on the Wii, in the case of disc-based software, it gets installed automatically (after the user is prompted).