Carding normally begins when a carder, such as Cvvstores or Bestsitetobuycvv, gets to a credit card processing system and gains access to a list of cards that were used to buy something through that system.
Carders then sell the list to a third party that can use this information to purchase gift cards. Of course, carders can also use the data themselves.
If a carder buys a gift card from an ecommerce store, they use a third-party (e.g. Undergrounddumpsshop and Cvvshoplv) to get goods and ship them to other locations. Carders can also sell goods to remain anonymous and reduce the risk of drawing attention.