What is a hard drive primarily used for?

A hard drive is primarily used for storing data and applications. It functions as a permanent storage device within a computer system, preserving information even when the power is turned off. This makes it essential for maintaining the operating system, software applications, user files, and other data that needs to be retained long-term.

The hard drive's role in storing applications allows users to access programs and files readily whenever they are needed. Unlike volatile memory, such as RAM, which loses its content when the device is powered down, the hard drive ensures that important documents, multimedia files, and system configurations are available on demand.

The other options relate to functions that do not pertain to the hard drive's primary purpose. For example, cooling the CPU is handled by cooling systems, not the hard drive. Internet connectivity involves network interfaces, such as Ethernet or Wi-Fi adapters, and is not a function associated with a hard drive. Additionally, running firmware typically occurs directly from a motherboard or other dedicated components rather than the hard drive itself. This reinforces the hard drive's specific role in data storage and application management within a computer system.