The IPTV glossary: every term you will meet, defined properly

IPTV, or Internet Protocol Television, is a method of delivering television as data packets over an internet connection instead of through a cable line, a satellite dish or a terrestrial aerial. The programming is identical; only the delivery path changes.

IPTV is a delivery technology, not a category of content and not a legal status. Telecoms companies have used it to deliver licensed television for two decades. What makes any given IPTV service legitimate or not is whether the operator holds distribution rights, which is a separate question from the protocol.

Linear television is programming broadcast on a fixed schedule that every viewer watches at the same moment, as opposed to on-demand content the viewer starts whenever they choose. A channel showing a match at 3pm is linear.

The distinction matters because linear and on-demand break in different ways. Linear cannot buffer far ahead — it is happening now — so it is far more sensitive to a weak connection than an on-demand film, which can fill several seconds of buffer before you notice a problem.

Video on demand, abbreviated VOD, is a library of recorded films and series a viewer can start, pause and resume at any time. Unlike a live channel, the file already exists in full on the server before playback begins.

Cord cutting is cancelling a cable or satellite television subscription and replacing it with services delivered over the internet. The term dates from around 2010, when broadband first became fast enough to make the switch practical for most households.

By 2026 the original promise has partly unwound: households that cut the cord to save money often ended up paying for a live-TV bundle plus three or four on-demand apps, which together cost as much as the cable package they replaced.

Geo-restriction is the practice of limiting access to a broadcast based on the viewer's detected location, because television rights are usually sold territory by territory. It is why a channel available in one country returns an error in another.

Geo-restriction is a rights consequence, not a technical limitation. Any service that operates across borders has to hold rights for each territory it serves, which is why coverage claims are worth reading carefully.

An IPTV player is the application that takes your subscription credentials, fetches the channel list and guide, and plays the streams. The player is separate from the service: the same subscription works in any compatible player, and the player you pick changes the experience considerably.

This separation confuses newcomers, because with cable the box and the service arrive together. With IPTV they are independent, which means a bad experience is often a player problem rather than a provider problem.

A set-top box is a dedicated hardware device that connects to a television over HDMI and does nothing but play television. MAG boxes are the best-known IPTV examples, running a Stalker portal rather than general-purpose apps.

Dedicated boxes trade flexibility for reliability. They will not run other applications, but they also do not compete for memory with a dozen background processes, which is why they tend to be stable on hardware that would struggle as a general-purpose streamer.

Hardware decoding uses a device's dedicated video chip to decompress a stream, rather than making the general-purpose processor do the work in software. It is dramatically more efficient and is usually a single toggle in a player's settings.

If a stream stutters on a device that should easily handle it, hardware decoding being switched off is one of the first things worth checking. Software decoding a 4K stream will overwhelm most streaming sticks.

Screen mirroring sends whatever a phone, tablet or computer is displaying to a television over the local network. It is a fallback route to the big screen on platforms that will not run a suitable player directly.

Mirroring works but is a compromise: it adds a network hop, drains the source device's battery, and typically caps effective quality below what a native player achieves. Treat it as a workaround rather than a setup.

Bitrate is the amount of data a stream uses per second, measured in megabits per second. It is a far better predictor of picture quality than resolution alone: a 1080p stream at 8 Mbps looks better than a 4K stream squeezed into 6 Mbps.

This is why resolution claims on their own mean little. A provider advertising 4K without stating a bitrate is describing the label on the box rather than what is inside it.

Adaptive bitrate streaming encodes the same content at several quality levels and lets the player switch between them mid-stream as available bandwidth changes. The result is a brief drop in sharpness instead of a stall when a connection dips.

Adaptive switching is why a stream can look momentarily soft and then recover. That behaviour is the system working correctly — the alternative to a soft picture for ten seconds is a frozen one.

Buffering is the pause that occurs when a player has run out of downloaded video and is waiting for more to arrive. The stall is a symptom; the cause is somewhere along the path between the source server and the device.

Roughly two-thirds of the buffering reports we investigate resolve to the viewer's own wireless link rather than to the service. The diagnostic that separates the two takes about a minute: play the same channel over Ethernet.

Latency is the delay between a moment happening and it appearing on your screen. In live IPTV it comes from encoding, segmenting, network transit and player buffering, and typically totals somewhere between eight and forty seconds behind the live event.

Latency matters most for sport watched alongside social media or a radio commentary, where being thirty seconds behind is obvious. It is not a fault, and reducing it means shrinking the buffer, which trades delay for stability.

Sustained speed is the throughput a connection can hold continuously under real conditions, as distinct from the peak figure a speed test reports in a short burst. Streaming depends on the sustained number.

A line that bursts to 200 Mbps but drops below 20 Mbps every evening will buffer, while a steady 40 Mbps line will not. If you test your connection, test it at the hour you actually watch television.

Uptime is the percentage of time a service is available. The figure is only meaningful with a measurement window and a definition of failure attached: 99.9% uptime allows roughly 43 minutes of outage a month, which is very different from 99% allowing over seven hours.

Zap time is how long a player takes to display picture after you change channel. It depends on how close the delivery edge is and whether the channel was already being served, which is why popular channels usually switch faster than obscure ones.

Zap time is the easiest thing to test during a trial and one of the most revealing. Under two seconds on a wired connection means the edge is nearby; five seconds or more suggests a single distant origin, and it will get worse under load.