Broadcast & live-production glossary

Back-timing means working backwards from a fixed out time through the running order, so each item gets a "must start by" time — telling you not just how long things last but when they must happen.

A browser source is a feature in OBS, vMix and similar tools that renders a web page (by URL) as a video layer with transparency — the mechanism behind most modern live-stream graphics.

A call sheet is the document telling everyone on a production who is needed, in what role, and when — their call times — along with contact details and key logistics for the day.

A call time is the time a crew or cast member is required to arrive for a production. Different roles have different calls, staggered so everyone and everything is ready by on-air.

A lower third is an on-screen graphic in the lower part of the frame that identifies the person or thing on screen — usually a name and title — overlaid on the live video.

OMUL (Overlay Mark-up Language) is Show Runner's declarative markup for building custom overlays — defining the on-screen elements, the entrance/exit animation, and author-defined controls.

An overlay is a graphic layered on top of live video, usually with a transparent background, so only the graphic shows over the picture — lower thirds, scoreboards, sponsor bugs and more.

A running order (or rundown) is the ordered, timed list of everything that happens in a show — each item, its duration and its cues — that the whole production team works from.

A show clock is a large, shared timer that shows a live production where it is against the plan — time into a segment, time remaining, and countdowns to hard outs like breaks.

A sponsor bug is a small, persistent on-screen logo — usually in a corner — that acknowledges a partner or sponsor while a show runs, kept subtle so it doesn't dominate the frame.

A teleprompter (or autocue) scrolls a presenter's script over or beside the camera lens so they can read while looking straight down the barrel, keeping eye contact with the audience.

A VT is a pre-recorded video clip played into a live show — an interview, a highlights package, a report or an insert — cued by the gallery at the right point in the running order.