R

RAM (Random Access Memory): The temporary memory storage area used to load program instructions and store files currently in use. Unless a file is permanently stored on a hard drive or other storage medium, changes to information in RAM will be lost when the computer is shut down.  

RAMDAC: Random Access Memory Digital-to-Analog Converter. A chip that stores the color palette and converts digital information into analog signals to a color monitor.It has three analog-to-digital converters and a static RAM for storing the color palette.Each color is composed of three values representing red, green, and blue, which together make up the chosen color.

ROM (Read Only Memory): A type of memory that contains data that can be read but not changed. Unlike RAM which is cleared of data when the computer is shut down, ROM is not dependent on electricity and can therefore retain the contents of its memory whether the PC is on or off. ROM usually contains data that tells the CPU how to run the computer and this is built in during the manufacturing process.  

Rotational Speed: Rotational speed is a major factor in hard drive selection as it determines how quickly data can be retrieved. Typical rotational speeds are 5400 RPM or 7200 RPM. The higher the RPM (revolutions per minute), the less time you'll spend waiting for your computer to access files.