What does encryption do to data?

Encryption is a process that converts plain text, which is data that is easily readable and understandable, into an unreadable format known as ciphertext. This transformation is achieved through complex algorithms and keys, ensuring that unauthorized individuals or attackers cannot easily access or interpret the original data. The primary purpose of encryption is to protect sensitive information, maintaining confidentiality and ensuring that only those with the correct decryption key or password can access the information in its original form.

In contrast, the other options mentioned do not accurately describe the function of encryption. For example, compressing data relates to reducing the size of data for efficient storage, which does not involve changing the readability of the content. Duplicating and securing data on multiple servers pertains to backup and redundancy strategies, enhancing data availability rather than changing its format. Furthermore, deleting sensitive information permanently indicates a removal process, as opposed to encryption, which focuses on protecting and obscuring access to data.