What is a cryptographic module?

Could you elaborate on the concept of a cryptographic module? As I understand, it plays a pivotal role in the security of cryptocurrency and financial transactions, but I'm not entirely clear on its functionality. Is it a hardware or software component? How does it specifically contribute to encryption and decryption processes? And furthermore, how does it safeguard the integrity of sensitive financial data? Could you provide a high-level overview of its importance in the cryptocurrency and finance landscape?