In the context of audio and visuals, AV generally stands for audiovisual or audio/video while A/V generally stands for audio/video    . In order to prevent confusion, this website will use AV to stand for audiovisual and A/V to stand for audio/video unless otherwise noted.
When it comes to audio, fidelity is, in the words of Wikipedia, "a term describing the faithfulness of an audio reproduction to the original sounds" .
The following are some abbreviations used for fidelity, resolution, and definition:
CE devices have two fundamental criteria: they are electronic devices, which means they use electricity, and they are designed for consumer use, which implies they are relatively affordable, easy-to-use, serve some sort of useful function that people are willing to pay for, and compatible with existing consumer devices and technology. CE AV devices form a key segment of CE, with televisions (TVs) being one such example .
Although there are a variety of groups involved in CE, one particularly important group is the CTA. The CTA was started in 1924 and has gone through a variety of name changes. Prior to its current name, the CTA was known as the Consumer Electronics Association (CEA). The name change from CEA to CTA was meant to broaden the scope of the association to include consumer technology companies that didn't produce CE devices . The CTA defines, maintains, and promotes a variety of standards  [23 pages 6+11]        and also produces the International Consumer Electronics Show (CES) .
1. AV. Wikipedia.
2. Audiovisual. Wikipedia.
3. Audio and video interfaces and connectors. Wikipedia.
4. AV receiver. Wikipedia.
5. Fidelity (disambiguation). Wikipedia.
6. Resolution. Wikipedia.
7. DEG, CEA, The Recording Academy® and Major Labels Reach Agreement on Definition for High Resolution Audio. June 12, 2014. (C) 2015 Consumer Technology Association.
8. Hi-Res Audio. (C) 2015 Consumer Technology Association.
9. Display resolution. Wikipedia.
10. Graphics display resolution. Wikipedia.
11. Computer display standard. Wikipedia.
12. List of common resolutions. Wikipedia.
13. Technology Glossary. (C) 2015 Consumer Technology Association.
14. AT&T HD Voice. (C) 2016 AT&T Intellectual Property.
15. crystal clear. Wiktionary.
16. Panasonic Arbitrator 360°HD Provides Unmatched High Definition Clarity for Mobile Digital Video Evidence Capture. Sept. 9, 2013. (C) 2016 Panasonic Corporation of North America.
17. Low fidelity. Wikipedia.
18. High fidelity. Wikipedia.
19. High-definition. Wikipedia.
20. Consumer electronics. Wikipedia.
21. Gary Shapiro. A New Name for Your Association. Nov. 6, 2015. Consumer Technology Association.
22. CEA EXPANDS DEFINITIONS FOR DIGITAL TELEVISION PRODUCTS. Aug. 31, 2000.
23. Kilroy Hughes, Dave Marsh, Tom McMahon and Skip Pizzi. A White Paper on ASTB, IDTV & HDTV Display Interoperability In the Year 2000 and Beyond. Sept. 7, 2000. Microsoft Corporation.
24. CEA Expands DTV Definition. TWICE. (C) 2016 by NewBay Media, LLC.
25. Greg Tarr. CEA Board Expands Definition Of DTV Product. TWICE. (C) 2016 by NewBay Media, LLC.
26. DTV Definitions.
27. Standards. (C) 2015 Consumer Technology Association.
28. About CTA. (C) 2015 Consumer Technology Association.