Accounting: in the context of security, accounting refers to the process of tracking and recording activities related to the security of an information system. It involves the collection, analysis, and reporting of security-related events, such as user logins, access attempts, system modifications, and other relevant activities.

Authentication: is the process of determining the identity of a user who attemps to access a resource. The commonly used authentication factors are:

1. Something you know: the user provides a secret piece of information that only he/she should know.
   E.g. passwords, PINs, or security questions.
2. Something you have: involves possessing a physical item, such as a smart card, security token, or mobile device.
3. Something you are: refers to biometric characteristics, such as fingerprints, facial recognition, iris scans, or voice recognition.
4. Somewhere you are: verifies if the user's current location aligns with their expected or authorized location.

Authorization: is the process of applying access control rules to a user process, determining whether or not a particular user process can access an object.

Availability: refers to the property of a system or resource being accessible and usable by authorized users when needed. Availability ensures that information, systems, and services are consistently and reliably accessible to authorized users, without disruption or compromise.

Confidentiality: refers to the concept of preventing the disclosure of information to unauthorized parties.  Confidentiality ensures that only authorized individuals or entities can access and view confidential or private information.

Integrity: refers to protecting the data from unauthorized alteration.  Integrity ensures that data and systems are protected from unauthorized modification, tampering, or corruption.

Non-Repudiation: refers to the assurance that a party cannot deny the authenticity, integrity, or origin of a communication, transaction, or action that they have performed. It provides evidence or proof that a specific party made a specific statement, preventing them from later denying their involvement.