For the casual listener, the type of file format your music comes in is probably an afterthought. But when you press play on whatever digital file you use, you may indeed notice a slight difference in how the music sounds. Of course, the song itself isn’t altered, the clarity is. Nonetheless, in the same way vinyl records are regarded as the best quality physical audio format you can get your hands on, different digital file formats, with different compression and bitrates, offer different levels of quality.

To understand music files, it’s important to understand the technical (but not too technical) concepts which set them apart. Digital audio files, in most forms, are compressed i.e. shrunk down to make them practically downloadable or streamable. Whether they are compressed and what is lost during that process creates a distinction between two different file types — lossy and lossless. As you may have already guessed, lossless files do not remove any data from the original file, while lossy indeed does.

A file’s bitrate also plays a significant role in audio quality. Bitrate is simply the amount of audio data that is processed during one second. It is measured in kilobits per second (kbps). Higher bitrate equals more audio data coming through at once, which equals greater sound quality. Thus, files that are not heavily and those which are lossless will generally have a higher bitrate.

Each format explained herein has differences between these parameters and particular applications which they’re useful for. File size, compression, bitrate, and overall sound quality, are important factors when working with audio files or simply deciding how you want to listen to something.

File Types

MP3

Short for MPEG Layer 3, MP3’s quickly became the standard during the digital revolution. Beginning way back in the early ’90s, downloading MP3’s, both legally and illegally, brought mass amounts of music to the masses. MP3’s have decent sound, but are particularly useful in a context that requires less space — like transferring large libraries of music over peer-to-peer file host platforms (ahem…Napster).

MP3s are a lossy format. The clearly successful concept was to allow users to maintain many quality audio files, without taking up too much space. The compression of MP3s takes place by removing extraneous audio data which normal human ears can’t detect and reducing the overall sound quality of aspects that are somewhat buried in the mix. MP3 sound quality varies based on how the file is compressed and its bitrate.

WMA

Windows, being the most popular operating system ever, has its own audio file format. It began for use with Windows Media Player, but evolved to be a bit more versatile. It is very similar to MP3s in that this lossy file uses compression, thus allowing it to fit in a small amount of storage space. It’s a fine format for casual listening, but not as widely supported as MP3s.

AAC

Also very similar to an MP3, the AAC file extension is a lossy file format, but includes some performance improvements. The AAC boasts better quality audio than an MP3, yet uses the same amount of disk space. Apple has adopted AAC for its music services. AAC is a very good format for casual listening.

FLAC

FLAC is considered amongst the best type of digital audio file available. It stands for Free Lossless Audio Codec and is an open-source audio format. FLAC is a lossless file type which compresses audio in a way which does not reduce its quality. Thus, with FLAC, the integrity of a recording is wholly maintained. It also has the added benefit of being able to hold information tags, which includes artist and album identification. Where available, FLAC is an excellent choice for listening to music.

WAV

WAV is a non-compressed, lossless audio format, which sports a relatively simplistic structure. Derived from RIFF (Resource Interchange File Format) it assures full, authentic sound quality, but also takes up quite a bit of space. Thus, there are specific instances where you’ll see WAV files, like in recording or mixing, and uploading digital audio works to certain platforms. WAV files are great in any context necessitating unadulterated authenticity.

AIFF

Audio Interchange File Format (AIFF) files were developed in the late ’80s by Apple. Similar to WAVs, AIFFs are uncompressed and lossless, thus retaining a higher quality of audio, but conversely, taking up a large amount of disk space. The AIFF file type, like WAV, will give you versatile capability in editing, mixing, and mastering. There is also one version of compressed AIFF file called the AIFF-C or AIFC. Sometimes you’ll see this file type as “AIF.” AIFF are also great for recording, mixing, and listening to high quality, unfiltered music, where the large file size is permitted.

Compressing All This into a Lossless Format

We can get into some more advanced, technical aspects as to how these files operate, not to mention when and where, but this article is not meant to go too far into that. The aim is to get a better sense of what these file types are used for and the corresponding quality with which they function.

So, hopefully next time you see one of these file extensions, you’ll know exactly what it means, and be able to recall its strengths and weaknesses, best applications, and even note the sound quality it has.