The Platters

• The platters are the discs of the hard drive where the computer information gets stored. Both sides of the platters store data.
  
  

Read/Write Heads

• The read/write heads write data to the hard disk platters and retrieve information from them. The read/write heads work in a manner similar to the needle on record players or the laser on CDs and DVDs.
  
  

Arm Assembly

• The arms contain the read/write heads. The hard drive controller moves the arms to the correct position on the disk. The arm assembly is comprised of the head sliders, head arms, sliders and actuator.
  
  

The Spindle

• The platters of a hard drive rest on the spindle. The spindle of the hard drive serves the same function as the spindle on a record player---it causes the disks to rotate.
  
  

The Spindle Motor

• The spindle motor causes the spindle to spin and allows the arm actuators to move the arms to the correct position on the hard disk drive.