According to Wikipedia, Citizens band radio (also known as CB radio) is, in many countries, a system of short-distance radio communications between individuals typically on a selection of 40 channels within the 27 MHz (11 m) band.
And A walkie-talkie (more formally known as a handheld transceiver, or HT) is a hand-held, portable, two-way radio transceiver. Both devices are used for communication. Though they are similar in type, they have some differences.
Differences between a CB radio and Walkie Talkie