A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

RAM
Random Access Memory. The main memory of a computer. Upgrading the available RAM will often dramatically improve a PC's performance. 128 MB of RAM is often standard for new PCs, although double this figure is much better. RAM is now very cheap.

RAW
Most digital cameras use the JPEG file format, one that most PC users will have encountered before. JPEG is a compressed image file enabling more images to be stored in memory, but at a loss of quality. RAW is the raw data from the image sensor before any processing is applied. In essence, it is a true representation of what the image sensor has seen. It is lossless and can capture data up to 12 bits, which is better than typical JPEG and TIFF formats. On the downside, a RAW file takes a great deal longer to process. Many prosumer and SLR cameras can save images in RAW format.

RDS
Radio Data System. The LCD display on the radio will display the radio station name and depending on the model of radio, some program information as well

RGB
Transmission system that splits the Red, Green and Blue signal to provide a clearer and more defined picture.

RMS
Root-Mean-Square. An amplitude measure of an electrical signal that reflects the net power capability of the signal or a speaker. Note that this differs from the peak power, which reflects the maximum instantaneous power capability

ROM
Read Only Memory. Where PCs store important information that they need to run the operating system and other software. Unlike RAM, ROM is permanent and its contents cannot be changed, replaced or deleted.

RPM
Revolution Per Minute or the number of full turns per minute.