According to the Wikipedia article what is Computer security$/$Cybersecurity$/$IT security defined as:

The encoding of computer systems such that they cannot be accessed unless two$-$factor authentication is used.

The protection of computer systems from theft or damage to their hardware, software or information as well as from disruption or misdirection of the services they provide

Is using hash algorithms of at least $128$ characters in length to protect computer systems

Using stateful firewalls $+$ IDS$/$IPS devices or next generation firewalls to protect computer systems from being accessed without permission