Streaming Terms Explained

Streaming has its own vocabulary, and most of it turns up on product boxes and settings menus without any explanation. This glossary collects the words that appear most often in our articles, defined in a sentence or two each. Where we have written a longer explainer, the entry links to it.

Ways of delivering TV

IPTV

Internet Protocol Television: TV channels and on-demand programmes delivered over an internet connection instead of an aerial, satellite dish or cable network. Our piece on why IPTV keeps gaining viewers explains the appeal.

OTT

"Over the top": a service that streams directly to viewers over the open internet, without the viewer's broadband provider being involved in the TV side.

Linear TV

Channels that run to a fixed schedule, where a programme starts at the same moment for everyone watching.

Video on demand (VOD)

Programmes and films you start whenever you like, rather than at a scheduled time.

Catch-up

A window during which recently broadcast programmes stay available to watch after they have aired.

EPG

Electronic programme guide: the on-screen grid that shows what is on each channel now and later.

Picture and sound

Resolution

How many pixels make up the picture. HD, Full HD and 4K describe increasing levels of detail.

HDR

High dynamic range: a way of encoding brighter highlights, deeper shadows and richer colour than standard video, if the screen supports it.

Bitrate

How much data per second a stream uses. A higher bitrate usually means fewer visible compression artefacts.

Codec

The method used to compress video or audio for streaming and decompress it for playback. A device must support a stream's codec to play it.

Adaptive streaming

A technique where the player switches between quality levels on the fly to match the connection, trading sharpness for smooth playback when needed.

Connection words

Bandwidth

How much data a connection can carry each second, usually written in Mbps. Our explainer on what Mbps means covers the units.

Latency

The delay before data arrives, measured in milliseconds. It matters most for live sport, calls and online games.

Buffering

The pause while a player loads enough video ahead to keep playing. Frequent buffering usually points to a slow or unsteady connection.

Powerline

Adapters that carry a home network through the electrical wiring, a fix for rooms the Wi-Fi does not reach.

VPN

A virtual private network: an encrypted tunnel between a device and a server, often used for privacy on public Wi-Fi.

Devices and apps

Streaming stick

A small device that plugs into a TV's HDMI port and adds streaming apps. See our streaming stick explainer.

Set-top box

A box that sits near the TV and delivers channels or apps, often supplied by a TV or broadband provider.

Casting

Sending a video from a phone or laptop to a TV or streaming device on the same network.

Profiles

Separate spaces within one account so each household member gets their own recommendations, history and, for children, age limits.

Game Mode

A TV setting that turns off heavy picture processing to reduce the delay between a controller and the screen.

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