IPTV Glossary: 60+ Terms Explained in Plain English

IPTV comes with a lot of jargon. This glossary explains the terms you will meet when setting up players, programme guides and home networks, in plain English and in alphabetical order. Where we have a full guide on a topic, the entry links to it.

In short: an IPTV glossary is a quick-reference list of the acronyms used in internet TV. Use the section headings below to jump to a letter range, and follow the links for the full explanation.

New to all this? Start with What Is IPTV?, and ask anything in the Beginners forum.

A–C

AAC. Advanced Audio Coding, a common compressed audio format used in streaming and broadcast.

AC-3 (Dolby Digital). A surround-sound audio format. Passing it through to a soundbar or AV receiver is covered in Audio Passthrough and Atmos.

Adaptive bitrate (ABR). A technique where a stream is offered at several quality levels and the player switches between them depending on your connection speed.

AV1. A modern, royalty-free video codec that compresses more efficiently than older codecs. Hardware support is still limited on older devices.

Bitrate. The amount of data used per second of video, usually measured in Mbps. Higher bitrate generally means better picture quality and a greater demand on your connection. See How Much Internet Speed Do You Need for IPTV?.

Buffering. The pause that happens when a player runs out of data to show. Causes and fixes are in How to Stop IPTV Buffering.

Catch-up. The ability to watch a programme after it has been broadcast. See Catch-Up, Timeshift and Recording Explained.

CDN (content delivery network). A network of servers placed close to viewers so streams load faster and more reliably.

Channel number / LCN. The logical channel number is the number a channel appears under in a guide or on your remote, such as BBC One on 1 on Freeview.

Codec. The method used to compress and decompress video or audio, for example H.264, HEVC, AV1 or AAC.

Container. The file or stream format that packages video, audio and subtitles together, such as MPEG-TS, MP4 or MKV.

Cloud DVR. Recording stored on a provider's servers rather than on your own device.

D–H

DASH. Dynamic Adaptive Streaming over HTTP, an adaptive streaming format similar in spirit to HLS.

Decoder. The hardware or software that turns compressed video back into pictures you can watch.

DRM (digital rights management). Technology that restricts copying and controls who can play protected content. See Widevine below.

DVB-T2. The digital terrestrial standard used by Freeview HD. It is relevant if you plan to receive aerial TV on your own network tuner; see Plex, Jellyfin and Live TV From Your Aerial.

DVR. Digital video recorder: a device or software that records TV. See also PVR.

Dolby Atmos. An object-based surround-sound format. Support depends on your device, app and audio equipment.

Dolby Vision. A dynamic HDR format. See HDR, Dolby Vision and Frame Rate.

EAC-3 (Dolby Digital Plus). A newer version of AC-3 that can carry Atmos in streaming apps.

Enigma2. A Linux-based operating system used on many satellite and cable receivers, which can also play IPTV streams. See Enigma2 for Beginners.

EPG (electronic programme guide). The on-screen schedule showing what is on now and next. See EPG and XMLTV Explained.

EPG offset. A time adjustment that corrects a guide showing programmes at the wrong time. See EPG Showing the Wrong Time.

Ethernet. A wired network connection, usually more stable than Wi-Fi for streaming. See Wi-Fi vs Ethernet for Streaming.

FAST channel. Free Ad-supported Streaming TV: live-style channels funded by adverts. See FAST Channels Explained.

FFmpeg. Open-source software for converting and processing audio and video, used behind the scenes by many media servers.

Frame rate. The number of pictures shown per second, such as 24, 25, 50 or 60 fps. UK broadcast TV is typically 25 or 50.

H.264 (AVC). A widely supported video codec used for HD streaming.

H.265 (HEVC). A more efficient successor to H.264, commonly used for 4K and HDR.

HDCP. A copy-protection system on HDMI connections. A faulty HDMI cable or device can cause HDCP errors and a black screen.

HDHomeRun. A family of network TV tuners from SiliconDust that send broadcast TV over your home network.

HDR10. The basic, static HDR format supported on most HDR TVs. See HDR, Dolby Vision and Frame Rate.

HDR10+ and HLG. Further HDR formats. HLG (Hybrid Log-Gamma) was designed with broadcast TV in mind.

HLS (HTTP Live Streaming). A streaming format that delivers short video chunks listed in an .m3u8 playlist.

HTTP / HTTPS. The protocols used to move web data. HTTPS adds encryption.

I–M

IGMP. The protocol used to join and leave multicast groups on a network. Some routers need IGMP snooping set up correctly for multicast to work.

Interlaced / progressive. Interlaced video (for example 1080i) draws alternate lines; progressive video (1080p) draws every line each time.

IP address. The numerical address of a device on a network.

IPTV. Internet Protocol Television: TV delivered as data over an IP network. See What Is IPTV?.

Jellyfin. A free, open-source media server that can also handle live TV and recording with supported tuners.

Kodi. A free, open-source media centre application. Use only the official repository and legal add-ons. See Kodi for Beginners.

Latency. The delay between something happening and appearing on your screen. Live streams usually run behind broadcast TV by a few seconds or more.

M3U. A plain-text playlist format. See M3U Playlists Explained.

M3U8. An M3U playlist saved in UTF-8 text, also the file type HLS uses for its chunk lists.

MAG box. A type of dedicated IPTV set-top box. See MAG Box Explained.

Mbps. Megabits per second, the unit for connection speed and bitrate.

MKV. A flexible container format commonly used for recordings.

MPEG-TS. The transport stream container used by digital broadcasting and many IPTV set-top boxes.

Multicast. One copy of a stream shared across a network and copied only where needed. Mostly used inside provider-managed networks.

N–S

NAS. Network-attached storage: a home server for files, often used to store recordings.

Network tuner. A TV tuner that connects through your network rather than directly to a computer.

OTT (over the top). Video delivered over the internet without a traditional TV provider's own network.

Passthrough. Sending audio untouched to a soundbar or receiver so it can decode it itself.

Plex. A media server and streaming platform, with free ad-supported live channels and optional live TV and DVR features with a subscription.

Port forwarding. A router setting that lets outside devices reach a service on your network. Handle with care for security.

PVR. Personal video recorder, another term for a recorder, also used for the recording feature in some players.

QoS (quality of service). Router settings that prioritise certain traffic. See Router Settings for Streaming.

Remux. Repackaging video into a different container without re-encoding it, which is quick and keeps quality.

Resolution. The number of pixels in the picture: for example 1920×1080 (Full HD) or 3840×2160 (4K).

RTMP / RTSP. Older streaming protocols you may still see in cameras and some live feeds.

Set-top box (STB). A box that connects to a TV to receive and decode channels.

Sideloading. Installing an app outside an official app store. See Sideloading Apps on Fire TV.

Subtitles / closed captions. Text of the dialogue, either embedded in the stream or delivered separately.

T–Z

Timeshift. Pausing and rewinding a live stream, normally by buffering it temporarily. See Catch-Up, Timeshift and Recording Explained.

Transcoding. Converting video from one format or quality to another, often on a media server, which uses processing power.

tvg-id. An attribute in an M3U playlist that identifies a channel so it can be matched to the right entry in an EPG. See EPG and XMLTV Explained.

tvg-logo / group-title. Playlist attributes that point to a channel's logo image and the group it belongs to.

Tvheadend. Open-source TV streaming server that receives broadcast TV and shares it on your network.

Unicast. One separate stream per viewer. This is how most internet video works.

VOD (video on demand). Programmes and films you start when you choose, rather than a live schedule.

VPN. A virtual private network encrypts your traffic and routes it through another server. See VPN for Streaming.

Widevine. Google's DRM system, used to protect streams on Android TV, Chrome and many other devices. Its security levels (L1, L3) determine the maximum quality some apps allow.

XMLTV. An XML-based format for TV listings, widely used to provide guide data to players and media servers. See EPG and XMLTV Explained.

Xtream Codes API. A login-based method some players use to load channels and guide data from a provider. Details of services are outside this site's scope.