A sales channel is a means of selling to your customers. Where can the customer purchase your product is the sales channel.
Types of sales channels are:
Using sales techniques, establish a network of customers business to business (B2B).
Selling your product in a physical shop or store.
self serve machines and kiosks.
Selling your product digitally or online.
Giving your product to be re labeled by reseller/s.
Distributing your product in bulk.
Import and export
Specialising in selling your product in a foreign market.
All these sales channels have pros and cons which also depend on your product and target segment.