<span>the three fundamental elements of an effective security program for information systems are Identification, Authentication and Authorization.The access control creates the user and assigns the rights to resources and authorization is giving permissions to the users to access the resources.The user who wants to enter the system should have a valid data t enter the system like password, fingerprint or any other type of recognition.</span>
the role of an os or operating system is the program that executes everything and makes the computer usable hope this helps
Real time system means that the system is subjected to real time, i.e., response should be guaranteed within a specified timing constraint or system should meet the specified deadline. For example: flight control system, real time monitors etc.
16. Branch or tree cutter
17.paint tape
18. Knife
19. Pots
20. Waterer