RAID
Hard Disk
A hard disk is a device that is used to store large amounts of data in a computer system. Hard disks differ from other memory because they are non-volatile, they retain the data even when they do not have power.
RAID
A hard drive does not inherently increase the security of a computer system.
hard disk is a collection power of computer and all the data are store in hard disk for the the long time save.
Operating system is obviously resides in computer memory which is hard disk. But the main (booting) files are loaded into ROM by bootstrap loader at the time of start of the computer. Have you ever seen your C drive (or the drive which is for system, program files). This drive is on hard disk ... so OPERATING SYSTEM PLACED MAINLY ON HARD DISK...
A computer hard disk or hard drive (fixed disk) is hardware.
disk defragmenter
The computer's hard disk stores data - be that the operating system, application programs, documents or virtual memory.Stores data that needs to be kept between times when the computer is turned off.
Hard Disk
The computer's hard disk is hardware.
No. A "system disk" is simply any disk which the computer can boot from and has an operating system installed on it. In most modern computer systems, the hard disk is normally the system disk. However most systems can also boot from a floppy disk, a cdrom, or even a USB thumb drive, providing of course that the media in question has the necessary system files on it. Many older systems did not have the ability to boot from the cdrom drive or USB drives. On these systems the only options were booting from the hard disk or floppy disk, so if the OS hadnt been installed to the hard disk yet (or it was broken) the only other option was the floppy disk.