Scratch space is typically disk storage on a hard drive that is used for temporary memory, especially while working in a program that can require a great deal of backup space. This region of a disc can then allow for storing temporary files from the Internet or from a program that is being used. While it does not function exactly like Random Access Memory (RAM), scratch space can often provide similar benefits for a computer user. It is typically best if it is located on a drive other than the computer's main drive, however, to ensure adequate storage is available even as new programs and files are added.
The purpose of scratch space on a computer hard drive is to provide the user of a system with additional memory while running applications. This is typically meant as temporary storage, much like a piece of scratch paper is used for temporary work in the real world. A photographer editing photographs on a computer, for example, may have them in scratch space on the computer while he or she is working on them. As the images are saved, then they are stored more permanently on the computer's hard drive, though they may still remain in temporary storage.
In some ways, scratch space operates similarly to the RAM on a computer. RAM is memory that is used by programs and applications, which is not permanent and is wiped every time power is shut off to a computer. Scratch space on a system is similarly temporary, though it is on a hard drive and so it does not rely on power for the data on it to be maintained. By using this type of storage, the RAM may be freed up on a system to focus primarily on other tasks, while the data is backed up on the scratch disc.
On many systems, the scratch space may be set up by default on the same hard drive as the Operating System (OS) and other programs. This can create problems, however, as additional files and software are downloaded for the OS. The hard drive begins to fill up from these types of programs, which leaves less room on the disc for scratch space. Issues may arise as the computer is no longer able to use the scratch region appropriately, due to other data being saved there. It is often best for the scratch data to be saved on a second drive, or a region of the disc partitioned specifically for this purpose.