Carding is the exchange and sale of credit cards (their data, not the physical cards.) And their use to buy online or, more difficultly, to transfer the money present in them.
The markets that sell credit cards are manifold and almost all are found in the deep web. How multiple markets are the guides on "how to do it" on the web.
Since they are resources accessible to all, carding cases have increased considerably compared to previous years.


But how do they steal credit cards?

They steal credit cards through various hacking techniques. For example, if a hacker finds a sql injection vulnerability on a bank site, the latter can steal all the data (including credit cards) in the bank's database.
ATTENTIONS I AM NOT SPONSORING THE TOPIC COVERED IN THE ARTICLE I AM ONLY BRINGING FOR THOSE WHO DO NOT KNOW IT.