Hard disk and Hard drive

Hard disk noun - A rigid magnetic disk mounted permanently in a drive unit.

Hard drive and hard disk are semantically related in permanent computer memory topic. In some cases you can use "Hard drive" instead a noun phrase "Hard disk".

Hard drive noun - Computer hardware that holds and spins a magnetic or optical disk and reads and writes information on it.

Hard disk and hard drive are semantically related in computer storage topic. You can use "Hard disk" instead a noun phrase "Hard drive".