In the context of data storage, what does the term “swap file” usually refer to?

The term "swap file" refers specifically to a portion of disk space utilized for virtual memory in a computer system. When the RAM (Random Access Memory) is full, the operating system uses the swap file to hold parts of data that are not actively in use. This allows the system to free up RAM for processes that require immediate access to memory, effectively extending the available memory resources.

Using a swap file is essential for managing system resources because it helps maintain performance even when the physical RAM is exhausted. It acts as an overflow space where inactive memory pages can be temporarily stored, ensuring that applications continue to run smoothly without crashing due to memory shortages. The swap space might reside on the same disk as the operating system or on a separate partition, allowing it to be accessed when needed.

The other options do not define a swap file correctly. An external storage device simply refers to any additional storage such as USB drives or external hard drives, a temporary backup is not specific to the concept of virtual memory management, and file system corruptions pertain to issues within the file system itself rather than a specific method of memory management.