system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do some websites require credit card CVC and some do not at checkout?

Seems if someone could charge without it, why is it needed some places? What's more, why is it needed a'tall?
gpt
Fraud prevention. Asking for the CVC is a much stronger proof that the purchaser actually has the card in question. The three digits of the CVC you are talking about are not stored electronically on the card so it can't be skimmed.  Far from a bullet proof security measure, but does add security for remote transactions such as online and avoids situations such as telephone operators asking for your PIN, which is the security measure for the card being present at the transaction.