Streaming comes with its own vocabulary. This glossary explains the terms you are most likely to meet when setting up and using IPTV, in plain language. Where a topic has its own article, you will find a link.
A–C
Adaptive bitrate (ABR)
A technique where the player switches between versions of a stream at different qualities depending on your connection. It reduces buffering at the cost of temporarily lower quality. See how IPTV works.
Aspect ratio
The shape of the picture, such as 16:9 for most TV content. A wrong aspect ratio setting makes the picture look stretched or cropped.
Bitrate
The amount of data used per second of video, usually in megabits per second (Mbps). Higher bitrates generally mean more detail and more bandwidth.
Buffer / buffering
The buffer is video downloaded ahead of what you are watching. Buffering happens when the buffer runs empty and playback pauses. See how to reduce buffering.
Catch-up (time-shift)
A feature that lets you watch programmes that aired earlier, where the service and player support it.
Codec
The method used to compress and decompress video or audio, such as H.264, H.265 (HEVC) or AAC. See video codecs explained.
D–H
Decoder (hardware / software)
The part of a device or player that turns compressed video back into pictures. Hardware decoding uses a dedicated chip; software decoding uses the main processor.
EPG (electronic programme guide)
The on-screen TV guide. See what is an EPG?.
Ethernet
A wired network connection. Usually more stable than Wi-Fi for streaming. See Wi-Fi vs. Ethernet.
Frame rate
The number of images shown per second, such as 25, 30, 50 or 60. Mismatched frame rates can cause judder.
HDCP
A copy-protection handshake between HDMI devices. Failures can cause black screens or error messages.
HDMI / HDMI ARC / eARC
HDMI carries video and audio between devices. ARC and eARC let a TV send audio back to a soundbar or receiver over HDMI.
HDR (high dynamic range)
Video with a wider range of brightness and colour. Formats include HDR10, HDR10+, HLG and Dolby Vision. See HDR explained.
HLS (HTTP Live Streaming)
A widely used method of delivering video in short segments, listed in .m3u8 playlists. See M3U vs. M3U8.
I–M
IPTV
Internet Protocol Television: TV delivered over an IP network such as the internet. See the beginner's guide to IPTV.
Latency
The delay between something happening and it appearing on your screen, or the delay in network communication.
Live TV
Channels that play in real time, as opposed to on-demand content.
M3U / M3U8
Playlist formats that list channels or stream segments. See M3U playlists explained.
Mbps
Megabits per second, the unit for internet speed and video bitrate. Not the same as megabytes (MB): 8 megabits make one megabyte.
P–S
Player (IPTV player)
The app that plays streams and shows channels and the programme guide. See how to choose an IPTV player app.
Resolution
The number of pixels in the picture: for example 1280×720 (720p), 1920×1080 (1080p) and 3840×2160 (4K UHD).
SD / HD / FHD / UHD
Common resolution labels: standard definition, high definition (720p), full HD (1080p) and ultra HD (4K).
Sideloading
Installing an app from outside the official app store. See sideloading apps safely.
Simultaneous connections
How many devices can stream on one account at the same time. Plans usually set a limit.
Subtitles / closed captions
Text versions of dialogue. Closed captions often include sound descriptions as well. See subtitles and audio tracks.
T–Z
tvg-id
An attribute in M3U playlists that links a channel to its programme guide data.
Unicast / multicast
Unicast sends a separate stream to each viewer; multicast sends one stream shared by many viewers on a network.
VOD (video on demand)
Films and series you can start whenever you like, rather than at a scheduled time.
XMLTV
A widely used XML format for TV listings, often used for EPG data.
Xtream Codes
A login format consisting of a server URL, username and password. See how Xtream Codes compares with M3U.
Frequently asked questions
What is the difference between Mbps and MB/s?
Mbps (megabits per second) measures speed; MB/s (megabytes per second) is eight times larger. Internet speeds and bitrates are usually given in Mbps.
What does "4K" mean exactly?
For TVs, 4K usually means 3840×2160 pixels, also called UHD.
Is VOD the same as streaming?
VOD is one type of streaming — on-demand content. Live TV channels are also streamed, but at scheduled times.
Using this glossary
This glossary covers the terms you are most likely to see when using IPTV. Bookmark it, and follow the links for detailed explanations of each topic.
More in this guide
- IPTV Subtitles and Audio Tracks: How to Turn Them OnSubtitles and alternative audio depend on the stream and the player. Here is how to find and use them.
- Video Codecs Explained: H.264, H.265 (HEVC), VP9 and AV1Codecs decide how efficiently video is compressed — and whether your device can play it smoothly. Here is what you need to know.