1. Confidentiality
Confidentiality involves protecting sensitive data private and keep safe from the unauthorized.
If sensitive personal information could be leaked, it is considered the confidentiality may be violated.
Or if the session or cookie of web services could be stolen, it is also considered the confindentiality may be violated.
2. Integrity
Keeping integrity means one should keep data not altered or unmodified, complete, and trustworthy.
If you’re familiar with the digital forensics, you should probabily heard of the integrity. The investigators of digital incidents have to keep the data(mostly the digital evidences) unmodified. If one modifies or even touched the evidence, it losts its integrity and won’t be accepted as digital evidences in worst case.
In common case, some online games checks the integrity by checking the game files. When a gamer modifies game files, the gamer can do more than the game developer intended. This is the most common cases of the game hacks, the player won’t die in FPS games for example.
3. Availability
If someone found an infinite loop that can be triggered by remote attacker in the firmware of factory operating machines, it may considered that the availability of machines can be violated and it can cause severe error in the factory that the machine is used.