Explanations first: codecs, formats, standards, and hi-res audio in plain English.
Explainer hub

What Is

This Stuff,
Exactly?

Start here when you want definitions, context, and plain-English explanations before diving into comparisons.

This section is for learning the language of codecs, formats, containers, standards, and hi-res audio without getting buried in jargon.
Concepts • Definitions • Context

How to use this page

Confused by terminology? Start here.

Need a decision? Use Compare.

Need the basics? Visit the Beginner guide.

Learn the Words,
Then the Decisions

These pages explain what things are before asking you to choose between them. That makes the whole site easier to use and much less confusing.

Best starting points

Codecs: What is a codec?

Audio quality: What actually matters?

Containers: What is a container format?

Standards: What is THX?

Hi-res: Hi-res audio explained

Playback: What is upsampling?What is a NOS DAC?What is a NOS R2R DAC?Bluetooth audio codecs

Advanced audio: What is DSD?

Production audio: What is DXD?

Practical audio choices

These pages answer the end-user question: which audio format should I actually use?

Best audio format for streaming

A practical guide to AAC, MP3, Opus, bitrate, bandwidth, and playback compatibility.

Best audio format for archiving music

Why FLAC is usually best for archives, when ALAC makes sense, and when WAV is useful.

Best audio format for iPhone

AAC for everyday listening, ALAC for lossless Apple libraries, and MP3 for universal compatibility.

Core concepts

These pages explain the building blocks: codecs, containers, formats, and standards.

What is a codec?

The simplest starting point: what codecs do, why they matter, and why media files need them.

Codec vs Format vs Standard

The most useful terminology page on the site. Start here if you are not sure what each term really means.

What is a container format?

A clear explanation of how MP4, MKV, and WebM package audio, video, subtitles, and metadata together.

What is THX?

Understand why THX is not a codec, but a playback and certification standard.

Hi-res audio explained

These pages cover bit depth, sample rate, PCM, DSD, DXD, SACD, and the higher-end side of digital audio.

Hi-res audio explained

The broad overview: bit depth, sample rate, formats, and whether hi-res audio actually matters in real listening.

What is upsampling?

A simple-to-advanced guide to sample-rate conversion, smoother playback, DAC filtering, and what upsampling can and cannot improve.

What is a NOS DAC?

Learn why non-oversampling DACs can sound direct, raw, or era-appropriate for older digital recordings and early electronic music.

What is a NOS R2R DAC?

A deeper look at resistor-ladder DACs, non-oversampling playback, analogue-like presentation, and how R2R differs from delta-sigma conversion.

What is DSD?

An explainer for Direct Stream Digital, the high-frequency 1-bit audio approach used in high-end playback formats. DSD is often discussed alongside DXD because DXD is commonly used for editing and mastering.

What is DXD?

A plain-English guide to Digital eXtreme Definition, the ultra-high-resolution PCM format often used when editing and mastering DSD recordings.

What is lossless audio?

A beginner-friendly explanation of FLAC, ALAC, WAV, lossy compression, and what lossless really means.

What is MP3?

A plain-English guide to MP3, lossy compression, bitrate, file size, compatibility, and why encoders such as LAME matter.

What is LAME MP3?

A focused explanation of the LAME MP3 encoder, VBR settings, 320 kbps MP3, and how encoding software relates to the MP3 format.

Why LAME MP3 still matters

A deeper end-user guide to how LAME MP3 works, why it stays compatible, and why encoder improvements did not break old MP3 playback.

What is AAC?

Learn how AAC works, why it often lives inside M4A/MP4 containers, and how it relates to streaming, Bluetooth, MP3, and Opus.

What is Opus?

A plain-English guide to the modern audio codec used for voice chat, video calls, streaming, low-bitrate audio, and Ogg Opus files.

Bluetooth audio codecs explained

A practical guide to SBC, AAC, aptX, LDAC, wireless compression, iPhone support, Android support, latency, and real-world sound quality.

What is bitrate?

Understand kbps, file size, streaming quality, and why bitrate matters most for lossy audio.

What is WAV?

A beginner-friendly explanation of WAV, PCM, studio workflows, file size, and metadata.

What is SACD?

A guide to Super Audio CD, its use of DSD, and why it remains a niche but important audiophile format.

PCM vs DSD

A comparison of the two major digital audio approaches, useful once you understand the basics.

DSD vs DXD

A focused comparison explaining why DSD is mainly a playback/distribution format while DXD is usually a production and editing format.

24-bit vs 16-bit audio

A practical explanation of bit depth, dynamic range, and whether higher numbers make a real listening difference.

FLAC vs ALAC

A useful companion page for lossless audio workflows, libraries, and playback compatibility.

FLAC vs WAV

A practical guide to choosing between compressed lossless files and uncompressed studio-friendly audio.

Not sure where to go next?

You want definitions

Use the Glossary for quick terms and short explanations.

You want a decision

Go to Compare if you already know what you are choosing between.

You want the basics first

Start from the Beginner guide and work upward.

Common format and compression questions

These pages answer the practical questions people usually have before they know the codec vocabulary.

Does converting audio or video lose quality?

Explains lossy conversion, lossless conversion, remuxing, and why bigger files do not automatically mean better quality.

Codec vs file extension

Clarifies why .mp4, .mkv, .m4a, .aac, .wav, and .flac do not all mean the same kind of thing.

Why are audio and video files so big?

Connects file size to bitrate, duration, resolution, frame rate, bit depth, and codec efficiency.

What is transcoding?

Explains re-encoding, compatibility conversions, Plex-style transcoding, and why quality can drop.

What is remuxing?

Shows how containers can change without re-encoding when the streams are compatible.

CBR vs VBR vs ABR

A focused guide to CBR, VBR, and where ABR works well: video audio, audiobooks, and MP3 radio streams.

More format explainers

New pages covering common file types and creator workflows.

What is sample rate?

44.1 kHz, 48 kHz, 96 kHz, music, video, and hi-res audio explained.

What is MKV?

Matroska Video, subtitles, multi-audio files, and the difference between containers and codecs.

What is WebM?

The browser-friendly container often used with VP9, AV1, Opus, and Vorbis.

What is OGG Vorbis?

Ogg containers, Vorbis audio, MP3 comparisons, Opus relationships, and game audio use.

What is AIFF?

Apple-style uncompressed audio, WAV comparisons, and professional audio workflows.

What is Apple ProRes?

Editing codecs, large files, production handoff, and ProRes vs H.264.

What is HEIC?

iPhone photos, HEIF, HEVC-related compression, JPEG compatibility, and storage savings.

Good future additions

Common questions

What is the best first page for beginners?

Start with the codec, container, bitrate, lossy, and lossless pages. Those concepts make the format-specific pages much easier to understand.

Why do some pages explain formats and others explain codecs?

Because media files involve several layers. A file extension may describe a container, while the actual audio or video inside may be compressed with a separate codec.

Should I learn audio or video formats first?

Start with the problem you actually have. If you are choosing music files, begin with MP3, AAC, FLAC, WAV, and bitrate. If you are exporting video, begin with MP4, H.264, H.265, AV1, and containers.

What does “used for” mean on format pages?

It describes the practical workflow where a format or codec is most common, such as music playback, studio editing, streaming video, archiving, voice calls, or disc-based audio.