RAID (Redundant Array of Independent (or Inexpensive) Disks)
RAID level 1, (Or RAID 1), storage systems use 2 identical hard drives that are created containing the same information. This type of RAID operation is called mirroring and provides a backup copy of the first drive. RAID level 5, (or RAID 5), uses 3 or more hard drives. Information is written to each drive simultaneously. This provides quicker disk access. Parity information is also written to each hard drive. This parity information is used to recreate lost data on a drive should it fail and need to be replaced. This type of RAID operation is called striping with distributed parity. There are several other RAID levels, but these 2 are among the ones most commonly used.
RAM (Random Access Memory)
Memory that the computer readily reads from and writes to. Once the computer is turned off the RAM is erased.
RISC (Reduced Instruction Set Computer)
A RISC CPU contains fewer instructions than a non-RISC CPU. One might think the RISC CPU would be inferior to the non-RISC CPU, but actually a RISC CPU is faster because of the fewer instructions. Many of the eliminated instructions are deemed fairly obsolete. One disadvantage of the RISC CPU is that it makes software more complex, because the software has to work around the eliminated instructions.
RGB (Red Green Blue)
Red, green, and blue, are the three colors an RGB monitor uses to create full color images. Combining red and green makes yellow. Red and blue combine to make magenta, a purplish color. By varying the proportions and combinations of each color the color possibilities are virtually endless.
RPM (Revolutions Per Minute)
The number of times an object rotates completely in a 60 second time period.
RTC (Real Time Clock)
The computer's RTC keeps track of time even while the computer is off. The clock is powered by a small battery located on the motherboard.
ROM (Read Only Memory)
Computer memory that never changes. ROM memory contains data that is permanently recorded on the ROM chip. ROM is memory that is normally never erased or altered. It is for reading only. Unlike RAM, ROM retains its data even when the power is off or disconnected.