Customers order and receive your products and services through channels. Channels require significant resources and are costly to establish. Expect channels to leave a significant footprint on the enterprise architecture.
Retail businesses tend to have stores and these days also a web shop. Some manufacturers sell their products through their own web shop as well as through wholesale stores and web shops.
Some businesses still use email and phone as their primary – perhaps only – channel.
If there are several customer segments and channels, I often include a matrix that shows which channels are used for which customer segments.