The correct answer is It is the practice of replacing or obscuring sensitive fields so they remain usable for testing and analytics.

Data masking means replacing or obscuring sensitive values so that the data retains structure and usefulness for testing and analytics while reducing the risk of exposing real personal information. Masking approaches include substitution, tokenization, redaction, and format preserving transformations and they are chosen to balance data utility and privacy for nonproduction use cases.

Cloud DLP is a Google Cloud service that can discover, classify, and deidentify sensitive data and it can perform masking operations, but naming a product does not define the general concept of data masking itself. The product is an implementation and not the definition.

A technique for reducing dataset size to lower storage costs describes compression, sampling, or archival strategies and it does not capture the idea of obscuring sensitive fields while keeping data usable for testing and analytics.

A method of encrypting confidential information to protect privacy refers to cryptographic protection that transforms data into ciphertext and is typically reversible with keys. Encryption protects data confidentiality but is different from masking because masking intentionally changes or hides values to enable safe use in nonproduction contexts.

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