Electrical Bus

Hard disk plays a significant role in the following important aspects of your computer system:

Performance: The hard disk plays a very important role in overall system performance, probably more than most people recognize (though that is changing now as hard drives get more of the attention they deserve). The speed at which the PC boots up and programs load is directly related to hard disk speed. The hard disk's performance is also critical when multitasking is being used or when processing large amounts of data such as graphics work, editing sound and video, or working with databases.

Storage Capacity: This is kind of obvious, but a bigger hard disk lets you store more
programs and data.

Software Support: Newer software needs more space and faster hard disks to load it
efficiently. It's easy to remember when 1 GB was a lot of disk space; heck, it's even easy to
remember when 100 MB was a lot of disk space! Now a PC with even 1 GB is considered by
many to be "crippled", since it can barely hold modern (inflated) operating system files and a
complement of standard business software.

Reliability: One way to assess the importance of an item of hardware is to consider how much
grief is caused if it fails. By this standard, the hard disk is the most important component by a
long shot. As I often say, hardware can be replaced, but data cannot. A good quality hard disk,
combined with smart maintenance and backup habits, can help ensure that the nightmare of
data loss doesn't become part of your life.

The hard disk drive in your system is the "data center" of the PC. It is here that all of your programs and data are stored between the occasions that you use the computer. Your hard disk (or disks) are the most important of the various types of permanent storage used in PCs (the others being floppy disks and other storage media such as CD-ROMs, tapes, removable drives, etc.) The hard disk differs from the others primarily in three ways: size (usually larger), speed (usually faster) and permanence (usually fixed in the PC and not removable).

Hard disk drives are almost as amazing as microprocessors in terms of the technology they use and how much progress they have made in terms of capacity, speed, and price in the last 20 years. The first PC hard disks had a capacity of 10 megabytes and a cost of over $100 per MB. Modern hard disks have capacities approaching 100 gigabytes and a cost of less than 1 cent per MB! This represents an improvement of 1,000,000% in just under 20 years, or around 67% cumulative improvement per year. At the same time, the speed of the hard disk and its interfaces have increased dramatically as well.