So in 2022 PCI Compliance is necessary for every merchant who stores, process and transmits customer's debit/credit card data. One must not handle a customer's critical data without proper security. The Payment Card Industry Data Security Standard (PCI DSS) provides steps that all merchants who process card payments, store or transmit credit, debit, or prepaid card information need to follow to provide secure transactions. Here is the article about pci glossary of technical terms at https://www.verygoodsecurity.com/learn/pci-compliance where you can find all info about it.