When we start talking about Operating System, The Security is most valuable thing to consider.

OS security is that the method of assuring OS uprightness, confidentiality and availability.

OS(Operating Systems) security refers to specified steps or measures wont to protect the OS from threats, viruses, worms, malware or remote hacker intrusions. OS security embraces all preventive-control methods, which protects any computer devices assets proficient from being stolen, edited or deleted if OS protection is arbitrated.

OS security could also be approached in some ways, including adherence to the following:

Performing regular OS patch updates

Installing updated antivirus engines and software.

Watching all incoming and outgoing network transit via a firewall.

Generating secure accounts with demanded perquisites only which is user management.

To maintain a good Security all the operating has evolved drastically, they have added counter measures in order to keep their OS safe for the users.

Every OS has started implementing these things:-

Authentication

Every os need A user credential to use their services otherwise they don’t let you use .

One Time passwords

One-time passwords offer extra protection along with usual authentication.

Program Threats

Operating system's procedures and kernel do the assigned task as instructed.

System Threats 

System threats implies to misuse of system facilities and network relationships to place user in trouble.