True.
Virtual memory is a technique that allows a computer to use its hard disk as an extension of its RAM (Random Access Memory) to address the issue of limited physical memory. The operating system divides the virtual address space used by a process into smaller chunks called pages, and these pages are swapped between the disk and the RAM as needed.
In this context, DRAM (Dynamic Random Access Memory) is treated as a cache for the hard disk. The operating system retrieves the required pages from the hard disk and stores them in the DRAM cache, which is faster to access than the disk. When the CPU needs to access a page that is not in the cache, the cache controller retrieves it from the disk and stores it in the cache.
In most modern systems, the DRAM cache is usually a write-back cache. This means that changes to the cache are first made in the cache and later written to the disk when the cache block is replaced. This approach is more efficient than a write-through cache because it reduces the number of writes to the disk and improves overall system performance.