Radio-Frequency RF Modulator - A device that transforms your television set into a computer display device. Also known as RF.

RAID (Redundant Array of Independent Disks) - A hard disk array that either increases the speed of disk input-output or mirrors the data for redundancy, or provides both of these features. Users may access the RAID as if it were one drive, although it may be divided into multiple partitions.

RAM Disk - A cross between a disk and random-access memory. Like a disk, it must be formatted before you can put files on it; also like a disk, it must be addressed by its volume name disk name or by its slot number. As with RAM, the computer can access the information on it very quickly. Also like RAM, what's stored on it is stored temporarily; when the power is turned off, the information on it is lost.

RAM - Random-access memory, sometimes referred to as main memory. The Macintosh RAM provides memory for system software and applications. In sleep mode, the contents of RAM are maintained. Shutting down the computer erases RAM contents. There are various types of RAM, including DRAM dynamic random-access memory and SDRAM synchronous random-access memory.

RCA - Radio Corporation of America.

Read-Only Memory - Abbreviated ROM. Permanent memory. Applesoft BASIC is stored in ROM along with other programs that regulate communication between the microprocessor and other parts of the computer system.

Read - To get information from a disk and put it in memory.

Record - The set of values that describes a single instance of an entity; in a relational database, a record is equivalent to a row.

Reference Movie - A .mov file created using a utility program like MakeRefMovie, available at no cost from Apple for Macintosh and Windows. The file contains the location of a streaming media file and can also contain the locations of multiple streaming files. A reference file linked from a web page, for example, can direct a client player to the on demand presentation encoded for its particular connection speed.

Referential Integrity - The rules governing the consistency of relationships.

Reflected Stream - A live broadcast delivered as a unicast stream. Movie and MP4 playlists also generate reflected streams.

Relational Database - A database designed according to the relational model, which uses the discipline of Entity-Relationship modeling and the data design standards called normal forms.

Relationship - A link between two entities that's based on attributes of the entities. For example, the Department and Employee entities can have a relationship based on the deptID attribute as a foreign key in Employee, and as the primary key in Department note that although the join attribute deptID is the same for the source and destination entities in this example, it doesn't have to be. This relationship would make it possible to find the employees for a given department.

Relayed Stream - A stream that is passed from one server to one or more other servers. Relays can also be used to generate a multicast stream. QTSS does not support relaying of MP3 streams.

Release Print - A positive print of a finished movie; the final product for distribution.

Remote Computer - The computer on the other end of the phone line; it can be across the room or across the country. You can use your Apple IIgs, a modem, and a communication application to communicate with a remote computer.

Rendering - The process of compositing elements together in a movie. This can include superimposing text on video or creating a transition on a clip. Rendering takes place any time the visual information for a frame of video needs to be modified.

Rendezvous - A protocol developed by Apple for automatic discovery of computers, devices, and services on IP networks.

Repeater - A device that amplifies an electrical signal received from one piece of transmission medium and passes it on to another, similar, piece of transmission medium. A repeater is commonly used to extend a cable beyond its recommended maximum length.

Report - A subset of the information in your data base. You may have a data base with information about your employees like their names, addresses, phone numbers, birthdays, social security numbers, and salaries. There are times when you want only a list of names and salaries that's one report. Other times you want names and phone numbers that's another report. You can generate all sorts of different reports from one data base.

Request - A message conforming to the Hypertext Transfer Protocol HTTP sent from the user's Web browser to a Web server that asks for a resource like a Web page. Response is a message conforming to the Hypertext Transfer Protocol HTTP sent from the Web server to the user's Web browser that contains the resource specified by the corresponding request. The response is typically a web page.

Reset Switch - A switch that restarts the computer in the event of a crash or freeze.

Reset - The key with a triangle on it that you can press in combination with Control and Apple key to restart an application.

Resolution - The degree of clarity of your display. A monitor has better resolution than a television set used as a monitor. An RGB color monitor has better resolution than a composite color monitor.

Response - A message conforming to the Hypertext Transfer Protocol HTTP sent from the Web server to the user's Web browser that contains the resource specified by the corresponding request. The response is typically a web page. Request is a message conforming to the Hypertext Transfer Protocol HTTP sent from the user's Web browser to a Web server that asks for a resource like a Web page.

Result Codes - A result code is a message the modem sends to the computer, indicating the result of an AT command or the status of a connection. If a telecommunications application is active on your computer, the result code appears on your screen. Result codes are reported either as numbers numeric or as words verbose. You use the Vn command to switch between these modes.

Retraining - Retraining is a process by which two connected modems can renegotiate the protocol and speed they are using, without having to reconnect. Retraining takes place when the line conditions change-for example, if the amount of static on the line increases. The process normally takes several seconds. You use the %En command to control retraining.

Return - A key that you can press to move the cursor to the beginning of the next line. Also used in many applications to accept choices or indicate that you've finished doing something and are ready to proceed.

Reusable Component - A component that can be nested within other components and acts like a dynamic element. Reusable components allow you to extend the WebObject's selection of dynamically generated HTML elements.

Reverse Telecine - The process that removes the extra frames from 3:2 pull-down video, returning it to its original 24 fps frame rate. Reverse telecine creates a one-to-one relationship between the video and film frames so that the cut lists are accurate. Reversing the 3:2 pull-down can be accomplished with hardware in real time during capture, but if you do not have the proper equipment, you can use the Cinema Tools Reverse Telecine feature.

RGB Color Monitor - Stands for Red Green Blue. A type of color monitor that can do what is impossible on most types of color monitor display text in color and in 80-column format.

Right Arrow - A key you can press in most applications to move the cursor one character to the right.

RISC - Reduced Instruction Set Computing. A smaller set of commands that optimizes efficiency and speed in microprocessing. Because RISC chips use a smaller instruction set, they operate much faster than the older CISC Complex Instruction Set Computing chips used in Intel-based machines and in older Macintosh systems.

Roaming - The seamless movement of a wireless node between two microcells. Roaming usually occurs in infrastructure networks built around multiple access points.

ROM Disk - ROM chips on a memory expansion card that can contain application programs.

ROM - Read-only memory. The Macintosh boot ROM contains system command sets.

Router - A device that connects networks together, isolating traffic within each network. The networks can be of the same type for example, two Ethernet networks or of different types for example, Token Ring and Ethernet. A router receives data transmitted from other networks and retransmits it to its proper destination over the most efficient route. A bridge-is a device that connects two networks of the same type together such as two Ethernet networks. The connected networks form a single large network.

Row - In a relational database, the dimension of a table that groups attributes into records. A way of designating the number of characters that fit on the computer's display.

RTAS - run-time abstraction services.

RTP (Real-Time Transport Protocol) - A network-transport protocol used for transmitting real-time multimedia content over multicast or unicast network services.

RTS Request to Send & CTS Clear to Send - Request to Send RTS and Clear to Send CTS are hardware-handshaking signals. When the computer is ready to send data, it sends a Request to Send RTS signal to the modem. When the modem is ready to receive data, it sends a Clear to Send CTS signal to the computer.

RTSP (Real Time Streaming Protocol) - A protocol for controlling a stream of real-time multimedia content. Sources of data can include both live feeds and stored clips.

Rule Editor - A tool used to edit the rules in Direct to Web and Direct to Java Client applications.

Rule - In the Direct to Web and Direct to Java Client approaches, a specification used to customize the user interfaces of applications developed with these approaches.

Run - What applications do when the computer is carrying out their instructions.