What is defragmentation?

The protection of computer's data, information, software and hardware from being damaged or lost is called computer security.

We need to apply computer security measures because of the following reasons:
        - For normal functioning of computer system.
        - For increasing the working speed and expectancy of a computer.
        - For proper security of computers.
        - For protection of computer hardware and software resources.

The hardware security refers to the protection of computer hardware from factors like dust, over heat, fluctuation of electricity and other intentional harm.

The hardware security measures are:
        - Regular maintenance.
        - Insurance.
        - Free from dust.
        - Fire protection.

The hardware components of computer system are very delicate devices and they may get damaged if the proper care has not been done regularly. The regular maintenance of computer helps us to find the problems in hardware. So, they can be repaired in time before they cause several damage. Hence, application of safety and regular maintenance helps us to keep our computer working condition.

A password is a secret word that gives gives a user or blocks an unauthorized users to access to particular file, program or a system. A system password helps to protect the files and programs from being used by an unauthorized person. So, the unauthorized users cannot make any changes in content of a computer. It helps to stop the spreading of computer viruses, and makes different software secure. So, system password is used in a computer.

The hardware is sensitive to electric voltage. It seeds normal electric voltage for functioning. The frequent failure of electric power can damage computer hardware, corrupts files, operating system, etc. So, to prevent this problems by providing the computer the constant voltage of power using paper protection devices, we need power protection devices for a computer.
Any four power protection devices are:
        - Volt...

The importance of UPS are:
        - It used as power protection devices.
        - It reduces/controls the fluctuation of electric voltage.
        - It saves the hardware/software from being damaged.
        - It provides backup electric power.

Data and software security refers to the process of securing data and software from being lost or damaged due to accidental or intentional harm.

The backup system helps to make the duplicate copy of data & software. If data and software get lost or damaged due to fluctuation of electric voltage, power failure , viruses or intentional then backup system helps us to recover the lost or damaged data or software from the backup copy of data and software. Hence, we need to backup data and software.

We can keep the hard disk and floppy disk in good condition by the following ways:
        - By using scan disk and antivirus programs.
        - By defragmenting the disks.
        - By keeping it in dust free environment.
        - Using power protection devices that prevents the damage of the disks.

We need to defrag a hard disk because:
        - To analyze the disk and rearrange the fragmented files.
        - To reduce/control fragmentation.
        - To increase the performance of disk operation.
        - To increase the contiguous spaces on the disks.

a.    When a hard disk of a computer system get damage or lost, we don't lose any data and information.
        - False

b.    Sometime by mistake user can delete important files.
        - True

c.    Hardware securing means securing hard disk from being damaged.
        - True

d.    Dust, fluctuation of electricity and overheat can damage hardware of the...

a.    An electric device that supply steady electric power when electricity is cut off.
        - UPS

b.    An electric device that supplies electric power when electricity is cut off.
        - UPS

c.    A secret word that gives a user access to a particular file, program or system.
        - Password

d.    A program that disinfects virus.
     ...