Inexpensive Chinese radios, such as those produced by Baofeng Technologies are popular as starter radios due to their low cost. They are also used as disposable or spare/back-up radios.
Learn about the internal architecture of the Baofeng UV-5RB in the Teardown Tuesday: Baofeng Amateur Radio Transceiver article on the All About Circuits website.
This article describes the disassembly process and includes a video of the tear down. It also includes circuit board photographs, a schematic diagram, block diagrams of the major components used in the radio, and links to data sheets for those major components.