Streaming glossary
Definitions are written for someone deciding what to buy, so each one says what the term changes in practice and where people get it wrong. Terms that get confused with each other are grouped first.
Words people mix up
Bonding vs failover
Bonding combines several internet connections into one larger pipe by splitting a single video stream across them and reassembling it at the far end. Failover keeps a second connection in reserve and switches to it when the first dies. Bonding adds bandwidth, failover only adds coverage. A dual-SIM phone does failover. A belaBOX, a LiveU, Peplink SpeedFusion, or Speedify does bonding.
Bitrate vs resolution
Resolution is how many pixels you send, bitrate is how much data you spend describing them each second. Resolution is what you ask for and bitrate is what you can afford. A 1080p stream starved of bitrate looks worse in motion than a well-fed 720p one, because the encoder pays for the extra pixels by discarding detail everywhere. On a weak connection, lowering resolution is the honest fix.
Upload vs download speed
Streaming is almost entirely an upload activity, so the download figure that internet providers advertise is close to irrelevant for going live. A 1000 Mbps cable plan with 20 Mbps upload is a 20 Mbps streaming connection. Mobile plans are worse offenders, because upload is where carriers throttle first and where congestion shows up soonest. Always read the upload number, and always test it at the hour you actually stream.
IRL streaming vs desk streaming
Desk streaming runs from a fixed location on a wired connection, so the internet is never the bottleneck and the hard problems are audio, lighting, and scene setup. IRL streaming runs from a phone or a backpack over cellular, where the connection is the bottleneck and everything else bends around it. The gear overlaps less than people expect: a webcam is useless outdoors, and a bonding device is pointless at a desk.
RTMP vs SRT
RTMP is the old, universally accepted way to hand a stream to a platform, and it fails badly on lossy connections because it runs over TCP and stalls when packets go missing. SRT is built for exactly those conditions: it recovers lost packets, tolerates jitter, and holds a mobile link together. Platforms mostly ingest RTMP, so a typical IRL chain is SRT from the field to your own relay, then RTMP from the relay onward.
Encoder vs capture card
A capture card converts a camera HDMI output into something a computer can see, and does nothing else. An encoder compresses video into a stream and sends it. On a PC, a capture card feeds OBS and the graphics card does the encoding. On an IRL rig, a hardware encoder such as a LiveU or a belaBOX does both jobs in one box. Buying a capture card will not, by itself, get you live.
Lavalier vs shotgun microphone
A lavalier clips to the speaker and stays a fixed distance from their mouth, which makes it the reliable choice when you are walking, in wind, or filming someone else. A shotgun mounts on the camera and picks up whatever it is pointed at, which captures more of the environment and more of the noise. Most IRL streamers end up on a wireless lav with a furry windscreen, and add a shotgun only when the ambience is the content.
Bitrate and quality
Bitrate
Bitrate is how much data your stream sends each second, measured in kilobits per second. It is the main lever on how a live stream looks, more than camera quality or resolution, because it sets how much detail the encoder can keep when the picture changes. Typical values run from about 3000 kbps for 720p30 to 6000 kbps for 1080p60 and far more above that.
Headroom
Headroom is the part of your upload speed you deliberately do not spend. Plan a stream at roughly 70% of your real sustained upload and leave the rest, because live video is bursty and mobile connections dip without warning. That unspent margin is what absorbs a spike before viewers see a buffer. Streaming at 100% of a speed test result is the most common cause of a stream that stutters on a connection that "should" be fine.
BRB screen
A BRB screen is the holding card viewers see when a stream loses its connection but the broadcast stays alive. On an IRL stream it is triggered by the uplink failing to carry the bitrate you set, usually in a tunnel, a lift, a crowd, or a dead spot between towers. Whether a drop becomes a short BRB or an ended broadcast depends on having a relay, since platforms end a stream when ingest stops.
CBR and VBR
CBR sends a constant bitrate whatever is happening on screen, and it is what platforms want because it makes your bandwidth use predictable and their delivery stable. VBR spends more during complex scenes and less during still ones, which is better for recording and worse for live. Use CBR for anything going out live. Save VBR for the local recording, where a fluctuating file size costs nothing.
Keyframe interval
A keyframe is a complete picture, and every frame between keyframes only describes what changed. The keyframe interval is how often you send a full one. Set it to 2 seconds for essentially every platform: it is what Twitch and YouTube ask for, it lets viewers join and switch quality quickly, and longer intervals save a little bandwidth at the cost of slow, glitchy joins.
Dropped frames
Dropped frames mean encoded video was thrown away rather than sent, and there are only two real causes. Network drops mean your connection could not carry the bitrate, and the fix is less bitrate or more uplink. Rendering or encoding lag means the machine could not produce frames fast enough, and the fix is a lighter encoder preset, hardware encoding, or a less loaded computer. OBS labels which one is happening in its stats panel.
Latency
Latency is the gap between something happening and a viewer seeing it. A normal Twitch stream runs roughly 8 to 20 seconds behind, low latency mode cuts that to a few seconds, and an SRT link into your own relay adds well under a second of its own. Latency matters most for chat interaction, which is why IRL streamers tune for it and why adding a relay hop costs less delay than people fear.
Connectivity
Bonding
Bonding splits one video stream across several internet connections at once and reassembles it at the far end, so two 5 Mbps modems can carry a stream neither could hold alone. It also survives one link dying mid-sentence. Bonding needs equipment or software built for it at both ends: belaBOX with SRTLA, a LiveU or TVU backpack, Peplink SpeedFusion, or a bonding service. Two SIM cards in one phone is not bonding.
Uplink
Uplink is your usable upload capacity: the sustained speed you can actually count on, not the peak a speed test reports on a good day. For planning purposes a phone hotspot is worth roughly 5 Mbps, a 4G modem about 4, a dedicated 5G modem about 8, and a home line effectively unlimited. Uplink is the number that decides what quality an IRL build can hold, and it is the one people overestimate.
SRT
SRT, or Secure Reliable Transport, is an open protocol built to carry video across unreliable networks. It re-requests lost packets within a time budget and smooths out jitter, which is precisely what a cellular connection does to video. That makes it the standard link between a mobile rig and a relay. Platforms mostly do not ingest SRT directly, so the relay converts it to RTMP for the last hop.
SRTLA
SRTLA is SRT with link aggregation: it takes one SRT stream and spreads it across multiple network connections, which is what makes cheap bonding possible. It is the protocol behind belaBOX, and it needs an SRTLA-aware receiver on the other end, which is why a belaBOX points at a belaBOX-compatible relay rather than straight at Twitch. SRT alone uses one connection at a time.
RTMP
RTMP is the long-standing protocol streaming platforms use to accept video, which is why every ingest page hands you an RTMP URL and a stream key. It runs over TCP, so on a clean wired connection it is completely fine, and on a lossy mobile one it stalls rather than degrades. Its universality is the reason relays exist: you send something robust to the relay, and the relay speaks RTMP to the platform.
WHIP
WHIP is a WebRTC-based ingest method that platforms have started adopting for very low latency, typically a second or less end to end. Whatnot uses it for OBS sellers and several platforms now offer it alongside RTMP. The trade is stability: WebRTC wants a steady wired connection and is less forgiving than SRT when packets go missing, so it suits a desk far better than a backpack.
Relay
A relay is a server between you and the platform. Your rig sends to the relay, the relay sends to Twitch or YouTube, and because the relay never drops its platform connection, a lost uplink becomes a short BRB screen instead of an ended broadcast. It is the single component that separates a mobile stream that survives a tunnel from one that has to be restarted and re-found by its audience.
VPS
A VPS is a rented virtual server, and for IRL streaming it is the cheapest way to run your own relay: a few dollars a month at Hetzner, DigitalOcean, or Vultr, running SRT or SRTLA receiver software. Renting one means you own the relay, choose the region, and pay for bandwidth rather than a subscription. It also means you maintain it, which is the real reason managed relay services exist.
Throttling and deprioritization
Carriers rarely cut unlimited plans off, they slow them down. Deprioritization means your traffic yields to other users once you pass a monthly threshold, typically somewhere between 30 GB and 100 GB, and it hits hardest in exactly the crowded places IRL streamers go. Video upload is usually the first thing to suffer. This is why the practical advice is two carriers on different networks rather than one bigger plan.
Data usage
Streaming data use is your bitrate times your hours, and it adds up faster than people expect. At 6000 kbps a stream burns roughly 2.7 GB per hour, so a four hour walk is about 11 GB, and a heavy month clears several hundred gigabytes. That number, not the price, is what decides which mobile plan works, because it determines how quickly you hit a deprioritization threshold.
IRL gear
IRL streaming
IRL streaming means broadcasting live from the real world rather than from a desk: walking a city, travelling, going to an event, or just running errands with an audience. Technically it is defined by its constraint, which is that the internet comes from cellular networks and moves with you. Everything distinctive about IRL gear, from bonding to batteries to weatherproofing, exists to work around that one fact.
IRL backpack
An IRL backpack is a wearable streaming station: a camera, an encoder, two or more cellular modems, a battery bank big enough for a full session, and a bag with enough airflow to stop it cooking. The encoder bonds the modems and sends to a relay. Builds run from a few hundred dollars using a phone and a mesh bag to well past fifteen thousand for a TVU or LiveU broadcast rig.
belaBOX
belaBOX is open-source software that turns a small single-board computer, usually an Orange Pi, into a bonding encoder for IRL streaming. It takes an HDMI camera feed and sends it over SRTLA across several modems at once. It costs a fraction of a commercial encoder and asks for setup effort in return, which is the trade at the heart of DIY IRL. belaBOX Cloud provides the matching relay if you do not want to run your own.
LiveU Solo
The LiveU Solo is a compact commercial bonding encoder: two modems, one HDMI input, and the LRT protocol carrying the stream to LiveU servers. It is the plug-in-and-go option, priced well above a DIY belaBOX and carrying a monthly service cost on top. It buys reliability and support rather than capability, which is worth it when a failed stream costs you money and not when you are learning.
V-mount battery
A V-mount is the broadcast standard battery format: a large brick that slides onto a plate and powers a camera, encoder, and accessories at once, usually with D-tap and USB outputs. It is the right answer for a cinema camera rig and overkill for a phone build, where a 20,000 mAh USB-C bank is lighter, cheaper, and airline legal. Check watt-hour limits before flying with either.
Power bank sizing
Estimate runtime from watt-hours, not milliamp-hours. A 20,000 mAh bank holds about 74 Wh on paper and delivers roughly 60 Wh after conversion losses, so a rig drawing 15 watts runs about four hours. Phone-only builds draw far less, backpack rigs with a camera and encoder far more. Airlines cap carry-on batteries at 100 Wh without approval, which is where most 25,000 mAh banks sit.
Gimbal
A gimbal motor-stabilises a camera or phone so walking footage is watchable rather than nauseating. For a phone-based IRL stream it is the highest-value accessory you can buy after a battery, because handheld walking video is the single most common reason viewers leave. Modern phones stabilise well while standing still and poorly while moving, which is exactly the case a gimbal fixes.
Cellular modem
A dedicated modem such as a Netgear Nighthawk holds a signal better than a phone hotspot, keeps a stable connection while its host device does other work, and takes an external antenna. A phone hotspot is free and works, but it shares one radio with everything else the phone is doing and gets hot. Bonded builds use dedicated modems because each one is a separate link.
Encoding
Encoder
An encoder compresses raw video into a stream small enough to send over your connection. It can be software running on a CPU, a dedicated chip inside a graphics card, a phone, or a standalone box in a backpack. The encoder sets the ceiling on resolution, framerate, and codec, so it is one of the three things, along with your uplink and the platform cap, that decide what quality a build can hold.
NVENC
NVENC is the dedicated encoding chip on NVIDIA graphics cards, separate from the cores that render games. Using it means encoding costs almost no game performance, which is why it is the default recommendation for single-PC streaming. Modern NVENC quality is close enough to a CPU encoder that the old quality argument is mostly settled, and x264 now only wins at slow presets on a machine doing nothing else.
x264
x264 is the software H.264 encoder, running on your CPU. At slow presets it produces excellent quality per kilobit, and it costs CPU time that a game also wants. It makes sense on a dedicated streaming PC or when you are encoding a light source. For a single machine that is also playing something demanding, hardware encoding on the GPU is the better trade.
H.265 (HEVC)
H.265, also called HEVC, reaches comparable quality at roughly 70% of the H.264 bitrate, which on a bonded mobile link can be the difference between holding 1080p60 and not. The catch is that both ends must support it: it helps immediately over SRT to your own relay, and only helps toward a platform that ingests HEVC, which is what Twitch Enhanced Broadcasting added. It also costs more encoding power.
AV1
AV1 is a newer, royalty-free codec that beats H.265 on efficiency and is being rolled out for streaming ingest, with hardware encoders on recent NVIDIA, AMD, and Intel graphics cards. Adoption is the limit rather than the codec: platform support is partial and viewer devices need to decode it. It is worth having on a new card and not worth buying a card for yet.
Capture card
A capture card turns an HDMI signal into a video source software can use, which is how a real camera or a game console gets into OBS. Internal cards sit in a PCIe slot, external ones connect over USB. What a capture card does not do is encode or stream by itself, and it will not fix a camera that overlays menus on its HDMI output or shuts off after thirty minutes.
Clean HDMI
Clean HDMI means a camera outputs only the picture, with no focus boxes, battery icons, or menu overlays burned in. Without it, a capture card faithfully records the camera user interface and your viewers see it. Clean output is a spec worth checking before buying, along with whether the camera can run indefinitely on mains power rather than stopping at a recording limit.
Software
OBS Studio
OBS Studio is free, open-source broadcasting software and the default tool for desk streaming. It composites scenes from cameras, capture cards, windows, and browser sources, then encodes and sends the result to a platform. It is the reference point everything else is measured against, and its main cost is a learning curve that alternatives smooth over at the price of flexibility.
Streamlabs
Streamlabs Desktop is a fork of OBS with built-in alerts, themes, and a friendlier setup flow, some of it behind a subscription. It trades resource use and flexibility for convenience. The practical answer is that Streamlabs gets a beginner live faster while OBS plus a free alert service does the same job for nothing and scales further. Both use the same underlying encoding.
Moblin
Moblin is a free iOS app for IRL streaming that sends SRT or SRTLA from an iPhone, with scenes, overlays, chat, and support for external cameras and bonding. It turned the phone in your pocket into a legitimate IRL rig and is the reason a usable mobile stream can now cost nothing. Android users reach for IRL Pro or Larix Broadcaster instead.
IRL Pro
IRL Pro is an Android app built for IRL streaming, handling SRT output, bitrate adaptation, overlays, and chat from a phone. It is the Android counterpart to Moblin and the reason the phone-first IRL path exists on both platforms. Which app you can use is determined by the phone you own, which is why choosing an encoder before choosing a phone is the wrong order.
Larix Broadcaster
Larix Broadcaster is a free mobile streaming app for both iOS and Android that pushes RTMP, SRT, or RIST from a phone. It is plainer than Moblin or IRL Pro and correspondingly reliable, which makes it a common backup app and a good fit when you want a camera feed out of a phone with minimum ceremony.
Scene and source
A scene is a saved arrangement of sources, and a source is any single input: a camera, a window, an image, a browser overlay, an audio device. Streaming software works by letting you switch between scenes live, so a typical setup has a starting screen, a main scene, and a BRB scene. Building them once is most of what setting up a stream actually consists of.
Stream key
A stream key is the password that tells a platform which channel an incoming stream belongs to, paired with an ingest URL in your broadcasting software. Every platform issues one in its creator dashboard. Treat it as a credential: anyone holding it can broadcast to your channel, so never leave it visible on screen, and reset it if you ever do.
Platforms
Twitch Enhanced Broadcasting
Enhanced Broadcasting is Twitch accepting higher bitrates and HEVC, plus multiple quality renditions sent from your machine rather than transcoded by Twitch. It is the route past the classic 6000 kbps ceiling and the only realistic way to put 1440p on Twitch. It costs upload bandwidth and encoding power, so it suits a wired desk far more than a bonded backpack.
Twitch bitrate cap
Twitch standard ingest is planned around 6000 kbps, which comfortably carries 1080p60 and cannot carry 1440p without visible smearing in motion. Partners and Enhanced Broadcasting channels go higher. This ceiling is why buying a sharper camera does not make a Twitch stream sharper, and why the platform you target has to be part of a gear decision rather than an afterthought.
Transcoding
Transcoding is a platform re-encoding your stream into lower quality options so viewers on weak connections can watch. It is not guaranteed on Twitch for smaller channels, which means everyone gets your source quality or nothing. That has a real consequence: streaming at a high bitrate without transcoding pushes away exactly the viewers whose connections cannot keep up.
Multistreaming
Multistreaming sends one broadcast to several platforms at once, usually through a cloud service such as Restream so your upload only carries a single copy. Sending directly to each platform from your own machine multiplies your bandwidth need by the number of destinations, which is fine on fibre and impossible on cellular. Check platform exclusivity terms before relying on it.
Vertical streaming
Vertical streaming means outputting a portrait canvas, typically 1080 by 1920, because that is what phone-first platforms display. It changes the whole setup rather than just a setting: framing, overlays, and camera mounting all differ, and a horizontal stream cropped to vertical looks like exactly that. Live selling platforms and TikTok expect it, and Instagram delivers only 720p regardless of what you send.
Live selling
Live selling is streaming to sell products in real time on platforms such as Whatnot, TikTok Shop, or eBay Live. The technical requirements invert normal streaming priorities: bitrate matters less, close-up detail and lighting matter enormously because buyers judge condition on camera, and a wired connection is close to mandatory since a dropped stream is a lost sale. Multi-camera setups are common and sometimes required.
Audio and camera
XLR
XLR is the professional audio connector, and an XLR microphone cannot plug into a computer directly: it needs an interface or mixer, which is a second purchase. USB microphones combine the two and are genuinely good now. The reason to go XLR is a specific microphone you want, or a setup with several inputs, not an assumption that XLR sounds better by itself.
Audio interface
An audio interface converts microphone signals into something a computer can record, supplies the power and gain a microphone needs, and gives you physical control over levels. For streaming it also lets you route several sources and monitor yourself without delay. A mixer does the same plus live blending of multiple inputs, which is what a multi-person setup needs.
Phantom power
Phantom power is 48 volts sent up an XLR cable to run a condenser microphone. Condensers need it, dynamic microphones do not, and sending it to a dynamic causes no harm. Most streaming microphones people recommend, including the SM7B, are dynamic and instead need a lot of clean gain, which is a different problem solved by a better interface or an inline preamp.
Gain
Gain is how much a microphone signal is amplified before it reaches your software. Quiet, hissy audio usually means a low-output dynamic microphone paired with an interface that cannot supply enough clean gain, so people compensate in software and amplify the noise floor with the voice. The fix is more gain in hardware, either a stronger interface or an inline preamp, not a louder software boost.
Wireless lavalier
A wireless lavalier is a clip-on microphone with a transmitter, feeding a receiver on the camera or phone. For IRL it solves the problem no camera microphone solves: keeping the speaker at a constant, close distance while moving through a noisy world. Add a furry windscreen before the first outdoor stream, because wind noise ruins more IRL audio than anything else.
Windscreen and deadcat
A windscreen is foam or fur over a microphone that stops moving air from hitting the capsule, and the furry version, called a deadcat, is dramatically more effective outdoors. Wind noise is not fixable in post or by software filters, because it saturates the microphone rather than layering over the voice. It is a cheap accessory that decides whether outdoor audio is usable at all.
Low-light performance
Low-light performance is a function of sensor size and lens aperture far more than resolution or price, which is why a large-sensor camera beats a higher-megapixel small-sensor one after dark. It matters more for IRL than for desk streaming, because a desk can simply add a light and a street cannot. Noise in dark scenes also eats bitrate, so a weak low-light camera degrades a whole stream.
PTZ camera
PTZ stands for pan, tilt, zoom: a camera you can aim remotely, either from software or a controller. In streaming it covers the second-angle problem, letting one person run a wide room shot they can reframe mid-stream without leaving their seat. Most connect over ethernet using NDI or SRT rather than HDMI, which changes how they fit into a setup.
Definitions reflect how this gear behaves as of 2026 and are kept in step with the planning rules the configurator uses. Ready to apply them? Plan a build or check what your connection holds.