Hard Drives
Although we may not see them every day, hard drives do immensely important behind-the-scenes work. Hard drives store government files, weather reports, your emails, the pictures on your digital camera, and many other things. In fact, hard drives are the backbone of the Internet: almost everything you see online is being stored on a hard drive. Hard drives use magnetic recording to store information: much like a cassette tape.
Magnetic Recording
Hard drives store data using electromagnets. On the basic level, the hard drive consists of the platter and the actuator. The platter is a hard material that is ferromagnetic (able to be magnetized). This is where your files are stored. The actuator arm, the piece that writes the data, magnetizes certain parts of the platter, giving it a value of 0 or 1. To read the data, the arm goes back over the data and interprets these magnetized areas.
The other parts of the hard drive simply allow this recording and reading process to happen. The IDE connector and jumper block connect the drive to the rest of the computer, allowing the computer's operating system to interact with the drive. The power connector supplies the electromagnet and other moving parts with electricity, allowing them to work. As we already know, the actuator arm writes the data, but it is controlled by the actuator and moves on the actuator axis. Finally, the spindle allows the platter to spin while data is being read from and written to it.