The three key objectives are:

Confidentiality
Integrity
Availability

Brief explanation

1. Confidentiality:
There are two types of confidentiality
          a) Data Confidentiality: Communication between two parties is kept secret or private without letting any unauthorized persons access the information.
    Example: When a company made a product design for its client, this objective makes sure the design information is shared securely with its client only.

          b) Privacy: It ensures that individuals control or influence the collection and storage of information about them, as well as who may be able to see their personal information.

2. Integrity:
        Integrity is further divided into two types.
     a) Data Integrity:
         It makes sure that both stored and transmitted information between two parties is modified only by the authorized persons in a specified manner.

     b) System Integrity: Ensures that a system performs its intended function without being negatively affected by intentionally or inadvertently unauthorized manipulations.

3. Availability:
          This objective is to make sure that systems are up and running promptly and authorized users are not denied the service.