Final answer:
Hard disk storage is referred to as secondary storage, which is non-volatile and retains data even when the computer is turned off.
Step-by-step explanation:
Hard disk storage is known as secondary storage. The primary storage of a computer system refers to memory that is directly accessible by the CPU, such as RAM (Random Access Memory). RAM is considered volatile because it loses its content when power is turned off.
In contrast, secondary storage, like hard disk drives (HDDs), provides non-volatile storage, meaning that the data remains stored even when the computer is turned off. Hard disk drives are used for storing large amounts of data permanently, including the operating system, applications, and personal files.
Hard disk storage is known as secondary storage. It refers to the permanent storage space in a computer system that retains data even when the power is turned off. Unlike volatile storage such as RAM, hard disk storage is non-volatile and can store large amounts of data for long periods of time. Therefore, the correct answer is a. secondary.