Walkie talkie ( Or handie Talkie..more formally known as a handheld transceiver) is a hand-held portable, two-way radio transceiver. Major characteristics include a half duplex channel (only one radio transmits at a time, though any 
number can listen) and a push-to-talk switch that starts transmission. Typical walkie-talkies resemble a telephone handset, possibly slightly larger but still a single unit, with an antenna sticking out of the top. Where a phone's earpiece is only loud enough to be heard by the user, a walkie-talkie's built-in speaker can be heard by the user and those in his immediate vicinity. Hand-held transceivers may be used to communicate between each other, or to vehicle-mounted or base stations.Since even a powerful commercial walkie-talkie is limited to a few watts of power output and a small antenna (the physical size of the package limits both battery capacity and antenna size), hand-held communication range is typically quite short, not exceeding the line-of-sight distance to the horizon in open areas, and very much less in built-up areas, within buildings, or underground.
number can listen) and a push-to-talk switch that starts transmission. Typical walkie-talkies resemble a telephone handset, possibly slightly larger but still a single unit, with an antenna sticking out of the top. Where a phone's earpiece is only loud enough to be heard by the user, a walkie-talkie's built-in speaker can be heard by the user and those in his immediate vicinity. Hand-held transceivers may be used to communicate between each other, or to vehicle-mounted or base stations.Since even a powerful commercial walkie-talkie is limited to a few watts of power output and a small antenna (the physical size of the package limits both battery capacity and antenna size), hand-held communication range is typically quite short, not exceeding the line-of-sight distance to the horizon in open areas, and very much less in built-up areas, within buildings, or underground. Many radio services permit the use of a repeater which is located at some high point within the desired coverage area. The repeater listens on one frequency and retransmits on another, so that reliable hand-held to hand-held unit range can be extended to a few score miles (kilometers) or further, using repeaters linked together. Walkie talkies for public safety, commercial and industrial uses may be part of trunked radio systems, which dynamically allocate radio channels for more efficient use of limited radio spectrum. And some cellular telephone networks offer a push-to-talk handset that allows walkie talkie like operation over the ceullular network, without dialling a call each time.Walkie talkies are widely used in any setting where portable radio communications are necessary, including business, public safety, outdoor recreation, and the like, and devices are available at numerous price points from inexpensive analog units sold as toys up to ruggedized ( waterproof or intrinsically safe) analog and digital units for use on boats or in heavy industry. Most countries, at the very least, will allow the sale of walkie-talkies for business, marine communications, and some personal uses such as CB radio, as well as amateur radio designs. Walkie-talkies, thanks to increasing use of miniaturized electronics, can be made very small, with some personal two-way UHF radio models being smaller.In addition, as costs come down, it is possible to add advanced squelch capabilities such as CTCSS (analog squelch) and DCS (digital squelch) (often marketed as "privacy codes) to inexpensive radios, as well as voice scrambling and trunking capabilities. Some units (especially amateur HTs, but also some commercial designs) also include DTMF keypads for remote operation of various devices such as repeaters. Some models also include VOX capability for hands-free operation, as well as the ability to attach external microphones and speakers.
Two way radio and Walkie talkie like from Cobra Kenwood Motorola and etc,