Video chat involves a surprising amount of jargon. Technical terms like latency, codec and NAT appear in troubleshooting guides, while safety terms like phishing and sextortion appear in warnings. This glossary explains forty of the most useful terms in plain English, with links to our more detailed articles where relevant.
Technical terms
Bandwidth — The amount of data your connection can carry per second, usually measured in megabits per second (Mbps). Video needs more bandwidth than audio or text. See improving video quality.
Bitrate — How much data per second a video or audio stream uses. Higher bitrates usually mean better quality but need more bandwidth.
Browser permissions — Settings that control whether a website can use your camera, microphone, location and other features. You grant them through a prompt and can change them any time. See fixing camera and microphone problems.
Codec — Short for coder-decoder. Software that compresses audio or video for sending and decompresses it on arrival. Common video codecs in browsers include VP8, VP9, H.264 and AV1; Opus is the standard audio codec in WebRTC.
Compression — Reducing the size of video or audio data so it can be sent efficiently. Heavy compression can cause blockiness or blur.
Data channel — A WebRTC feature that sends arbitrary data, such as text messages, directly between browsers. See how in-call text chat works.
DTLS — Datagram Transport Layer Security. The protocol WebRTC uses to set up encryption between browsers.
Echo cancellation — Processing that removes the sound from your speakers that your microphone picks up, preventing your partner from hearing themselves. See fixing echo and audio problems.
Encryption — Scrambling data so only the intended recipient can read it. WebRTC encrypts all audio, video and data in transit.
Frame rate — How many individual images per second make up a video, measured in frames per second (fps). Higher frame rates look smoother.
getUserMedia — The browser interface websites use to request access to your camera and microphone.
ICE — Interactive Connectivity Establishment. The process browsers use to find a working network path between them. See STUN, TURN and NAT explained.
ICE candidate — A possible network address where a browser can be reached, exchanged during call setup.
IP address — A numerical address identifying a connection on the internet. See peer-to-peer video and your IP address.
Jitter — Variation in how long data packets take to arrive. High jitter causes choppy audio and video.
Latency — The delay between something happening at one end of a call and being seen or heard at the other. Lower is better.
MCU — Multipoint Control Unit. A server that mixes multiple video streams into one for group calls. See peer-to-peer vs server-based video.
NAT — Network Address Translation. The system that lets many devices share one public IP address, which makes direct connections between devices harder.
Packet loss — When some pieces of data never arrive. It causes freezes, glitches and robotic-sounding audio.
Peer-to-peer (P2P) — A connection where two devices send data directly to each other rather than through a central server.
Resolution — The number of pixels in a video frame, such as 640x480 or 1280x720 (720p). Higher resolutions look sharper.
SDP — Session Description Protocol. The format browsers use to describe their media capabilities in an offer or answer during call setup.
SFU — Selective Forwarding Unit. A server that receives each participant's video and forwards it to others, common in group calls.
Signalling — The exchange of setup messages between browsers, through a server, before a WebRTC call begins. See how WebRTC works.
Simulcast — Sending the same video at several quality levels at once, so a server can forward the best version for each viewer.
SRTP — Secure Real-time Transport Protocol. The encrypted format WebRTC uses to send audio and video.
STUN — Session Traversal Utilities for NAT. A server that tells your browser its public address, helping establish direct connections.
TURN — Traversal Using Relays around NAT. A server that relays media when a direct connection is impossible.
Upload speed — How fast your connection can send data. Crucial for sending your video, and often lower than download speed on home connections.
WebRTC — Web Real-Time Communication. The open standard that enables live audio, video and data in browsers without plugins.
WebSocket — A persistent two-way connection between a browser and server, used by many platforms, including JustChill Live, for real-time signalling and matching. See how random matching works.
Safety and social terms
Catfishing — Pretending to be someone else online, often using stolen photos or videos, to deceive people.
Community guidelines — A platform's rules about acceptable behaviour. Read ours in our Community Guidelines.
Data minimisation — Collecting only the personal data necessary for a specific purpose. See why no-signup platforms matter.
Doxxing — Finding and publishing someone's private information, such as their address or workplace, without consent, usually to harass them. Protecting identifying details is the best defence. See personal information you should never share.
Grooming — When someone builds trust with a person, often a young person, in order to exploit or abuse them. It is one reason platforms like JustChill Live are strictly 18+. See our parent's guide.
Online disinhibition effect — The tendency for people to behave with fewer restraints online than in person, for better or worse. See anonymity online.
Phishing — Tricking people into revealing passwords, card numbers or other sensitive information, often through fake links or websites. See common video chat scams.
Sextortion — Threatening to share intimate images or video of someone unless they pay or provide more content. See what to do if someone threatens you.
Trolling — Deliberately provoking or upsetting people online for amusement. The best response is usually to disengage and skip. See handling inappropriate behaviour.
How to use this glossary
You do not need to memorise any of these terms to enjoy random video chat. But knowing a few of them can make troubleshooting faster and help you recognise safety risks sooner. If your partner's video freezes, you will know it is probably packet loss or low bandwidth, not something you did. If someone sends you a strange link, you will recognise phishing. And if someone threatens you, you will know that what they are doing has a name, that it is a crime, and that help is available.
Keep learning
If you want to go deeper, our articles on how WebRTC works and STUN, TURN and NAT explained cover the technology behind video chat, while our privacy checklist and Safety Guide cover staying safe. For everything else, browse the full collection on our Articles page.