| Term | Description |
| RAM | Random Access Memory is the workspace of your computer. It's the area that stores the information and data for processing by the computer's CPU. Retrieving data from the hard drive is much slower, but once the data is loaded into RAM, it can be accessed instantly and randomly. RAM is volatile, which means that once you turn off the power, all data in memory disappears. RAM is stored in chips on small circuit boards called SIMMs or DIMMs, that attach to the motherboard. |
| Read/Write Head | A small electro-magnet in a drive that skims above the surface of a disk or platter and reads information from, or writes data to, the disk. |
| Real Mode | Real Mode is an operating mode that allows the execution of only one program at a time. Programs can only access 1024K of memory and use a 16-bit data path. The improvement over this is Protected Mode which allows support for virtual memory and multitasking (running more than one program at a time). Protected Mode programs can access addresses above 1024K and can use a 32-bit data path. |
| Reduced Write Current | In older hard drives, there were the same number of sectors near the center of the platter or disk as there was in the outer tracks. To get the same number of bits in each sector, the bits had to be placed closer together in the center tracks. Using the same magnetic current to write information to the center tracks sometimes affected adjacent data. To solve this problem, a method was devised that reduced the current as the heads got closer to the center. |
| Refresh | The process of rewriting, recharging or updating the data sent to a specific device, such as a monitor or RAM. |
| Registry | The Registry is a database used by Windows95, 98 and NT to store user preferences, setup, device, and system configuration. The Registry files are vital to the proper execution of the Operating Systems. |
| Resolution | The image on your computer's monitor is made up of tiny dots called pixels (picture elements). The total number of pixels used to draw the image on the screen determines the Resolution and is defined by the number of pixels across and the number of pixels down. i.e. 640x480. |
| ROM | Read-Only Memory. Data or code written to chips (or CDs) that is burned on at the factory and can't be erased or changed. |
| ROM BIOS | See BIOS. |
| Root Directory | The main or first directory created on a drive or disk when it's formatted by the Operating System. |