The Wii Channels section featured additional non-game channels that could be downloaded and used on your Wii. Whenever Nintendo released an anti-homebrew update, they often updated the Wii Shop Channel and made their servers incompatible with the older version, in order to convince people to update. Most of the software that was in the shop is still on NUS, but the software is simply hidden from plain view, unless if they were already purchased by the user, in which case the ticket is detected on the NAND. After this, the Wii Shop Channel downloads the title from NUS, and decrypts it using the key found in the ticket.
When a channel is purchased, a small piece of data known as a ticket is downloaded from Nintendo. The shop can still be accessed, however, only the Wii U Transfer Tool and The Legend Of Zelda: Skyward Sword Save Data Update Channel are downloadable.
On January 31, 2019, the Wii Shop Channel was shut down. The latter two could be purchased using Wii Points, which were obtained by either buying a points card at a retail store, or by entering your credit card into the channel. You could download lots of different content for your Wii, this includes new channels, Virtual Console games and WiiWare. The Wii Shop Channel was the place Nintendo created to buy/download official software from the internet directly to your Wii.