What is the function of a hard disk in a computer?

The function of a hard disk in a computer is to store data permanently. Hard disks are designed to retain large amounts of information even when the power is turned off, which distinguishes them from other storage solutions like RAM. While RAM (temporary memory) is used for active processes and data that the CPU needs quickly, hard disks maintain applications, files, and the operating system itself for long-term access.

Additionally, hard disks can hold a variety of data formats, including documents, photos, videos, and software programs, making them crucial for everyday computer operation. The capacity of modern hard disks allows for extensive data storage, while their structure enables random access to data, making it efficient for users to retrieve information as needed. This permanent storage capability is essential for a functional and practical computer system.