A hard disk is a type of magnetic disk that is used to store data in a computer . When you save data or install programs in a computer , then the information is typically written to your hard disk.
These hard disks are a type of spindle of magnetic disks, called platters, which record and store information.
Since the data is stored magnetically, the information that is recorded in the hard disk remains intact even when you turn the computer off. This is an important distinction between hard disk and RAM or memory, which is reset when the power of the computer is turned off.
In this, the hard disk is placed inside a hard drive that reads and writes data into the disk. These hard drives also transmit data back and forth between the CPU and the disk.
When you save the data in the hard disk, then the hard drive has to write thousands of Zeros and Ones, even if not millions then in your hard disk. It is an amazing process to think, but a good way is to backup the data .