Final answer:
Integrity is the aspect of information security that ensures data remains unaltered and consistent unless authorized modification occurs. It is a critical part of the CIA triad, which includes Confidentiality and Availability.
Step-by-step explanation:
The concept in question that ensures data is not changed when it is not supposed to be is integrity. Integrity is one of the three main goals of information security, often referred to as the CIA triad: Confidentiality, Integrity, and Availability. Integrity ensures that data remains accurate and consistent over its lifecycle, and has not been altered in an unauthorized manner. This protection covers data being stored as well as during transmission. Measures to ensure integrity include access controls to prevent unauthorized personnel from altering data, checksums and cryptographic hashes to detect alterations, and version controls to track changes over time.