---
next:
  text: 'Release Notes'
  link: '../release-notes/all-changes-ee'
---

# Reference

This chapter is a comprehensive reference guide for the MQTT protocol and EMQX-specific features. Here, you will find detailed information and explanations about MQTT versions, terminologies, features, and reason codes, empowering you with a deeper understanding of the MQTT protocol and the functionalities provided by EMQX.