What is a characteristic of hard disk memory?

Hard disk memory is characterized by its ability to retain data even when power is removed. This non-volatile nature means that all stored information remains intact without the need for a continuous power supply, distinguishing it from volatile memory types, such as RAM, which lose their data once powered down. Hard disks are primarily designed for long-term storage, making them suitable for keeping operating systems, applications, and user data securely.

In contrast, other mentioned characteristics do not align with the fundamental properties of hard disk memory. For instance, volatility, temporary storage, and speed comparison to RAM are not applicable since hard disk memory's defining feature is its durability and capability to store data persistently.