R

RAM

Random Access Memory, which allows any byte in memory to be accessed randomly. Well, isn't that self-referential? Random access means to be able to get something without disturbing its neighbors. For example, if you wanted to fetch byte 10, you could just nab byte 10 instead of moving aside bytes 1 through 9 on your way to 10. Still not working for you? OK, imagine that you have been given the gift of teleportation. You are in San Francisco and want to go to New York. Close your eyes; think New York; open your eyes and you are there. You didn't have to travel through Missouri to get there, you just went there. That's how random access works.

RAM disk

A portion of RAM set aside to act as if it were physical storage, like a disk drive. The opposite of virtual memory. Compare with virtual memory.

read-me file

A document that contains important information for the user, usually about the pitfalls of installing software.

resolution

A measurement of the clarity of an image. Resolutions are given for monitor displays (how many pixels are on the screen), printer output (dots per inch), and image files (number of pixels).