What are the characteristics of virtual memory?

The characteristic that allows more memory than is physically available is fundamental to the concept of virtual memory. Virtual memory acts as an extension of physical memory (RAM) by utilizing a portion of the hard drive (or SSD) as if it were additional RAM. This allows the operating system to run larger applications or multiple applications simultaneously, even if the total required memory exceeds the actual physical memory of the computer.

When a system uses virtual memory, it manages the allocation of memory space effectively by moving data in and out of physical memory and hard drive storage as needed. This process enables users to run larger programs or multitask more efficiently without encountering memory shortages.

Considering the other aspects mentioned in the options, while they touch on the concept of virtual memory, they do not encapsulate its primary defining feature as clearly as the correct answer. The notion of "storing pages not in use" pertains to how memory is managed but does not emphasize the allowance for more memory than what is physically available. Similarly, while executing pages and combining RAM with hard drive space are parts of how virtual memory operates, they do not highlight the key benefit of extending memory beyond physical constraints.