https://www.techtarget.com/searchsecurity/definition/data-masking
Masking is a technique that involves replacing or hiding some parts of sensitive information with symbols or characters, such as asterisks (*) or Xs. Masking can help safeguard the confidentiality of sensitive information while allowing limited access to authorized individuals, because it obscures the original data without altering its format or structure. For example, masking can be used to hide some digits of a credit card number or a social security number. Deidentification, hashing, or salting are other techniques that involve transforming or modifying sensitive information, but they do not allow limited access to authorized individuals. Reference: https://www.ibm.com/docs/en/ims/14.1?topic=masking-data