Reference
Internet Radio Glossary
Plain-language definitions for the streaming, codec, and broadcast terms used across the ice Radio FM directory. If a station description mentions HLS, AAC, or Icecast and you're not sure what it means, the answer is here.
A
- AAC
- Advanced Audio Coding — a lossy compressed audio format used by many modern radio stations. AAC at 64 kbps sounds roughly equivalent to MP3 at 128 kbps, so streams use less bandwidth without losing quality.
B
- Bitrate
- How many kilobits of audio data per second the station transmits, measured in kbps. Higher bitrate = better fidelity but more bandwidth. Common values: 64, 96, 128, 192, 256, 320 kbps.
- Buffer
- A small in-memory cache the player keeps a few seconds ahead of playback. It absorbs brief network hiccups so audio plays smoothly even when packets arrive late.
C
- Codec
- Short for coder/decoder — the algorithm that compresses and decompresses audio. Common audio codecs are MP3, AAC, OGG Vorbis, and Opus.
- CORS
- Cross-Origin Resource Sharing — a browser policy that controls whether one site can fetch data from another. Some radio streams require ice Radio FM to proxy them because the original server doesn't send the right CORS headers.
D
- DASH
- Dynamic Adaptive Streaming over HTTP (also called MPEG-DASH) — an open standard for adaptive bitrate streaming. Less common in radio than HLS but used by some larger broadcasters.
G
- Genre
- The musical or content category a station broadcasts: rock, jazz, news, talk, sports, electronic, classical, world, and so on. Stations may be tagged with multiple genres.
H
- HLS
- HTTP Live Streaming — a streaming protocol developed by Apple that breaks audio into short HTTP-served chunks. It works in virtually every modern browser and is firewall-friendly because it uses standard HTTP.
I
- Icecast
- An open-source streaming media server widely used by independent broadcasters. Most "internet radio" stations you find online run on Icecast or its sibling SHOUTcast.
L
- Live listener count
- The approximate number of people listening to a station right now. ice Radio FM tracks this anonymously via short-lived heartbeat pings from active players.
M
- MP3
- MPEG-1 Audio Layer III — the most widely supported lossy audio format. Plays in every browser and on every device. Less efficient than AAC at low bitrates but universally compatible.
O
- OGG Vorbis
- A free, open-source lossy audio codec. Comparable quality to MP3 at the same bitrate but without patent restrictions. Supported by Chrome, Firefox, and Edge.
P
- Playlist
- On ice Radio FM, a saved list of stations you can play in sequence. Different from a music playlist — radio playlists are collections of live stations, not individual songs.
- Proxy
- A relay server that fetches audio on your behalf when the broadcaster's stream isn't directly playable in your browser (CORS, mixed-content, or geo-block reasons). ice Radio FM proxies streams transparently when needed.
S
- Sample rate
- How many audio samples per second the stream contains, measured in Hz (e.g. 44100 Hz = CD quality). Most internet radio uses 44.1 or 48 kHz.
- SHOUTcast
- A proprietary but free streaming server developed by Nullsoft (creators of Winamp). Predates Icecast and is still used by many stations, especially in the US.
- Stereo / Mono
- Stereo streams contain separate left and right channels for spatial sound; mono streams have a single channel. Most music stations are stereo; many talk and news stations are mono to save bandwidth.
- Stream URL
- The direct internet address of a station's audio feed. ice Radio FM stores it but never displays it raw — listeners use the play button instead.
T
- Tombstone
- A permanent "this is gone" marker. When ice Radio FM removes a station for good, the URL returns HTTP 410 (Gone) instead of 404 so search engines deindex it faster.
Want to know more?
See how to listen, browse the FAQ, or jump into the directory.