This article provides a comprehensive overview about radio receivers, focusing on their classification, operating principles and quality indicators. Radio receivers can be classified based on various criteria, including frequency range, modulation types, applications and etc. The operating principles are explored in detail, comprising the processes of signal reception, amplification, demodulation and others. In addition, key quality indicators such as sensitivity, selectivity, interference immunity are analyzed to evaluate performance and reliability of radio receivers. By understanding these aspects, users can make informed decisions when choosing radio receivers for a variety of applications, from personal use to professional broadcasting.