PCI DSS is a set of security standards that businesses must adhere to in order to accept and process payments by card. The PCI DSS is needed to protect consumers from fraud and identity theft. This security standard emerged in the mid-2000s as a response to the rapid growth of payment card fraud and data theft.
PCI compliance is required by banks, not by the government. Failure to be PCI compliant results in a hefty fine per non-compliant transaction.