Streaming Glossary: 60 Terms Explained Simply

Streaming comes with a lot of jargon. This glossary explains 60 common terms in plain English, grouped alphabetically, with links to our in-depth guides where a topic deserves more than a sentence or two. Use your browser’s find function (Ctrl + F or Cmd + F) to jump to a term.

A–C

• Adaptive bitrate streaming: a technique where a stream is available at several quality levels and the player switches between them as your connection changes, lowering quality instead of stopping.
• Aspect ratio: the shape of the picture, written as width to height, for example 16:9 for widescreen TV.
• AV sync (lip sync): how well sound and picture line up. See how to fix audio out of sync.
• Bandwidth: the capacity of a connection, usually given in Mbps; how much data it can carry per second.
• Bitrate: how much data a stream uses per second. Higher bitrates can look better but need faster connections. See what is bitrate?.
• Buffer: video downloaded in advance and held in reserve so playback continues smoothly.
• Buffering: the pause that happens when the buffer runs out. See how to stop buffering.
• Cache: temporary files an app stores to work faster. Clearing it can fix slow or glitchy apps; see clearing cache.
• Casting: sending video from a phone or computer to a TV, for example with Google Cast or AirPlay. See casting from phone to TV.
• Catch-up TV: watching recently aired programmes from the guide. See what is catch-up TV?.
• CDN (content delivery network): a network of servers in many locations that delivers video from a server close to you.
• Codec: the method used to compress and decompress video or audio, such as H.264, HEVC or AAC.
• Connection (simultaneous stream): one device playing at a time on your account. See simultaneous streams explained.
• Cord cutting: cancelling traditional cable or satellite TV in favour of internet-based services.

D–F

• Decoder: the hardware or software that turns compressed video into pictures. See hardware vs software decoding.
• Dolby Vision: an HDR format that adds scene-by-scene picture information; needs support in the content, device and TV.
• DRM (digital rights management): technology that protects licensed content from unauthorised copying.
• EPG (electronic program guide): the on-screen TV guide. See what is EPG?.
• Ethernet: a wired network connection, usually more stable than Wi-Fi. See Wi-Fi vs Ethernet.
• Fire OS: the operating system on Amazon Fire TV devices, based on Android.
• Frame rate: how many pictures are shown per second, such as 25, 30, 50 or 60 fps. Higher rates make motion smoother.
• Full HD: a resolution of 1920 × 1080 pixels, also called 1080p. See SD vs HD vs 4K.

G–L

• Google TV: Google’s TV interface, built on Android TV, used by many smart TVs and streaming devices. See IPTV on Android TV and Google TV.
• H.264 (AVC): a very widely supported video codec.
• HDCP: the copy-protection system used over HDMI. 4K content usually requires HDCP 2.2 or later on every device in the chain.
• HDMI: the cable and connection standard used between streaming devices and TVs.
• HDMI-CEC: a feature that lets devices control each other over HDMI, for example using a streaming stick remote to turn the TV on.
• HDR (high dynamic range): brighter highlights and richer colour than standard dynamic range. See 4K HDR requirements.
• HDR10: the baseline HDR format supported by nearly all HDR TVs.
• HEVC (H.265): a more efficient codec than H.264, common for HD and 4K streams; needs device support.
• HLS (HTTP Live Streaming): a widely used streaming format that delivers video in short segments listed in an M3U8 playlist. See M3U vs M3U8.
• IPTV (Internet Protocol Television): TV delivered over an internet connection. See what is IPTV?.
• Jitter: variation in network delay; high jitter causes live streams to stutter. See jitter and packet loss.
• Latency: the time data takes to travel across the network and back, in milliseconds.
• Live TV (linear TV): channels watched as they are broadcast, following a schedule.

M–P

• M3U: a plain-text playlist format widely used for IPTV channel lists. See what is an M3U playlist?.
• M3U8: a UTF-8 M3U playlist, also used for HLS streams.
• Mbps (megabits per second): the unit used for internet speeds and bitrates. Eight megabits equal one megabyte.
• Mesh Wi-Fi: a home network made of several units that work together to cover a larger area.
• MPEG-TS (transport stream): a container format for continuous video and audio, common in broadcasting and IPTV (.ts).
• Packet loss: data that fails to arrive; even small amounts can cause freezing.
• Passthrough (bitstream): sending Dolby or DTS audio unchanged to a soundbar or receiver for decoding.
• Player app: the app that plays streams and shows the guide; it contains no channels itself. See what is an IPTV player?.
• PVR / DVR: a personal or digital video recorder, which saves programmes to watch later.

Q–S

• QoS (quality of service): a router feature that prioritises certain devices or traffic, such as your TV.
• Resolution: the number of pixels in each frame, such as 1280 × 720 or 3840 × 2160.
• SD (standard definition): lower-resolution video, typically 480p or 576p.
• Sideloading: installing an app from a file instead of an official store. It carries security risks; see how to spot unsafe streaming apps.
• Streaming stick: a small device that plugs into an HDMI port and adds streaming apps to a TV. See Smart TV vs streaming stick.
• Smart TV: a TV with a built-in operating system and app store, such as Tizen, webOS or Google TV. See find your TV’s operating system.

T–Z

• Timeshift: pausing, rewinding or restarting live TV, or watching it shortly after broadcast.
• tvg-id: an M3U attribute that links a channel to its TV guide entry. See adding an EPG URL.
• tvOS: the operating system on Apple TV. See IPTV on Apple TV.
• UHD / 4K: a resolution of 3840 × 2160 pixels, four times as many as Full HD.
• Upscaling: a TV or device enlarging a lower-resolution picture to fill a higher-resolution screen.
• User agent: a short text an app sends to identify itself to a server; change it only if your provider asks.
• VOD (video on demand): films and series you can start whenever you like, rather than at a scheduled time.
• VPN (virtual private network): an encrypted tunnel between your device and a VPN server. See VPN for streaming.
• XMLTV: an XML format for TV listings, used to supply guide data to players.
• Xtream Codes login: a server URL, username and password that many IPTV players accept. See what is an Xtream Codes login?.

Summary

Most streaming terms describe one of four things: how video is compressed (codec, bitrate, resolution, HDR), how it travels (bandwidth, latency, jitter, HLS), how it is organised (playlist, M3U, EPG, Xtream Codes) or how you watch it (player app, streaming stick, casting). When a term leads to a problem, the linked guides explain how to fix it.