What is Integrity according to Computer Security?

In the context of computer security, "integrity" is the "I" in the "CIA" triad, i.e. Confidentiality, Integrity, and Availability. Integrity refers specifically to data being protected from unauthorized changes. The changes could be intentional, accidental, or simple corruption. Intentional changes could be things like an intruder trying to cover his tracks by modifying the log files to delete entries showing his activity or someone hacking into a a school database to change their grade in a class. Man-in-the-middle attacks can be attacks on integrity where a message is intercepted, modified, and then forwarded to the intended recipient. Accidental changes would be things like someone deleting data by executing the wrong command. An example of corruption would be a software flaw that allows overwriting database files when someone inserts a string that is longer than intended in a data field and the input is not validated before the write is executed.