Defintions

Public and Personal Communications 
 * // PDA: It stands for **personal digital assistant**, it is a electronic organiser which was aimed to replace diaries, "to do lists" and address books ﻿ //
 * // GPS: It stands for **global positioning system**, it is a navigational system that invloves satellites and computers that can determine the latitude and longitude of a receiver on earth. //
 * // Cell/mobile phones: They are﻿ electronic devices used for mobile telecommunications (mobile telephone, text messaging or data transmission). //
 * // Digital Radio and TV: ﻿ A digital radio carries information as a digital signal, a TV is a widely used telecommunication medium for transmitting and receiving moving images, either monochromatic ("black and white") or color, usually accompanied by sound. //
 * //Embedded systems:// //﻿// Are computer systems designed to perform one or a few dedicated functions often with real-time computing constraints (examples that carry embedded systems are : microwave, washing mashine , etc... ).