Glossary of AV Terminology

Aspect Ratio

The ratio of the projection or display screen’s width x height.  Most legacy systems and Microsoft Powerpoint presentations use the almost-square 4:3 ratio.  The lecture room cameras, video conference systems, and screens display in the 16:9 ratio. See hereon how to change your 4:3 Powerpoint to 16:9.


Aspect Ratio of Old and New Screens

Audience Response System (ARS)

Allows for students to respond to questions posed in a live presentation, and for cumulative responses to be displayed on screen. The MD Program currently uses the polling feature of Zoom.



A video file type used in the recording process and is not usually distributed. Stands for Audio Video Interleave format, created by Microsoft Corporation.


Stands for Bring Your Own Device, and refers to the requirement of some classrom technologies to operate on students' own devices, such as their laptops and smart phones.

Document camera

A device that displays either 3D objects or pre-written text to the local screen or to videoconference audiences. One of these is in each of the four large classrooms used by the MD Program.


The MD Program's learning management system, implemented in August 2018.


The former name of Elentra.

Far (Site, Audience, or Participant)

See Remote (Site, Audience, or Participant).

Field recording

A video and audio recording method involving taking video and audio equipment to locations outside of the studio. Discovery Commons’ field recording units can provide multi-camera, live webcast and computer display resources.

File sizes 

The measure of the size of a computer file, usually measured in bytes (b), megabytes (Mb), kilobytes (Kb), and gigabytes (Gb). Video, audio, photography and graphics can take up a large amount of space on a hard drive.  A one-hour MP4 video file can often be well over 1 Gb. Some video-file types, such as AVI, are better suited for recording but are too large for posting on the web. Other file types, such as MP4 and MP3, are more compressed and, therefore, better suited for web distribution and streaming. There is software that can convert large file sizes to smaller sizes for sharing or posting to the web.

Adobe Flash

Adobe Flash is a deprecated platform for showing video on the web. Flash has now been superceded by html5, which has taken precedence as a more universal format for web viewing.

Flipped classroom

Teaching method that requires students to watch a pre-recorded lecture before attending an interactive session with a teacher.  This method contrasts to the traditional method in which students attend a lecture at school and then review the work at home.

Front projection

A projector’s beam projects to the screen from the audience side or front of the display. The large classrooms used by the MD Program in the Terrence Donnelly Health Sciences Centre in Mississauga use front projection.

Green Screen

Green curtain or green wall that allows for the removal of the colour green from the video spectrum, in order that the green background can be replaced with something else, such as a photo or video of another location.

HD, High Definition

High Definition quality video is any video with resolution higher than standard definition. HD is currently typically 720p,1080i, 1080p, or 4k. The numbers refer to the number of lines of resolution from the top to the bottom of the screen in a 16:9 aspect ratio, and the p and i after the numbers refer to the way the lines of resolution are scanned.  The screen displays in the videoconference-equipped lecture rooms, as well as many of the recently installed meeting rooms, are 720p in a 16:9 aspect ratio.

Host (1)

A web host is a service that provides servers on which individuals and organizations can place material in order that it can be accessed from a website. Videos at Discovery Commons, for example, are hosted with the media hosting company Panopto. A link to the video (url) is provided, and that link gets posted on a website, and when a user clicks the link, the video streams and can be viewed.

Host (2)

In a classroom videoconference, the host refers to the site from which the lecturer is presenting; in a fully remote videoconference, using a tool such as Zoom, the host refers to the account holder managing the call.


See Terrance Donnelly Health Sciences Centre


Computer language for content on the internet, it includes features for playing audio and video within web pages with special considerations for playing media on smart phones. 

Lectern Intercom

Located on the classroom lecterns, this intercom allows someone in the lecture room to communicate with a technician. It has a silver panel with a white microphone button.

help button

Lectern Microphones

The long-stemmed microphone on the lectern is one of two default microphone options for presenters. The second option is a wireless lapel microphone usually found on top of the lectern or in a cubby in the lectern. If you stay behind the lectern, you can use the lectern microphone, but if you plan to move away, even a little, from the lectern while you are teaching, you must use the wireless lapel microphone in order that the remote site can hear you.

Sound adjustments are done by technicians, but there is a Privacy button on the touch panel on the lectern that will mute and unmute the lectern microphones. Pressing the Privacy button from flashing to solid changes both lectern microphones from mute to live; pressing it again so it is flashing sets them back to mute. Using the mute feature is advised for any time you are behind the lectern before and after your lecture, but are not teaching to the class.

Lecturer Cameras

In each of the videoconference-equipped lecture rooms, there is one camera pointed towards the lectern. The cameras allow the lecturer to be seen by students at the remote site, and they also facilitate a better view of the lecturer for those in the back of the room where the lecturer is presenting.

Lecturers are advised not walk up the aisles, as the cameras will not be able to follow them.

Local (Site, Audience, or Participant)

Refers to the site, audience or participant in the videoconference location that is where the presenter is.


Audio file format that compresses and reduces the file size from the original version while delivering a good quality reproduction.


Video file format that compresses and reduces the file size from the original version while delivering a good quality reproduction. Most of Discovery Commons’s edited video productions are output as MP4 files for viewing on a website.


A link to an item, such as a video, that is placed on a website. The item resides on a server somewhere, and when the user clicks the posted link, the video plays from that server.

Privacy button

A button on the touch panel in the lecture rooms that allows the lecturer’s microphones to be muted. When the Privacy button on the touch panel is flashing, both the lectern microphone and the wireless microphone connected to the lectern are muted. When the Privacy button is not flashing, both microphones are live. 

Rear Projection

The projector’s beam projects onto the screen from behind. The large classrooms used by the MD Program in the Medical Sciences Building at the St. George campus use rear projection.

Remote (Site, Audience or Participant)

Refers to the site, audience or participant in the videoconference location that is not where the presenter is.


File-sharing application for transferring large files available to Faculty of Medicine staff. This resource is useful for those who want to share large video and audio files with faculty, staff, and students both within and outside of the University of Toronto.

Contact for account information.

SMART Monitor

The interactive monitor at the lectern of the videoconference-equipped lecture rooms that allows the presenter to use a stylus to annotate and advance slides. Annotations are displayed on the lecture room screens and are recorded along with the rest of the presentation (if recording has been initiated).


One of the applications in the O365 suite, Stream is a video delivery platform that was used for delivery of MD Program videos from 2019 to 2022. Although current videos are now on another platform (Panopto), students in can still view their earlier years' lectures on Stream.


Refers to the delivery and receipt of online video provided by a host service, allowing the user to view the video without downloading it.

Student Microphones

Student Microphone

There is one microphone for approximately every two student seats in the large classrooms used by the MD Program. These microphones have a push-to-talk button, and depending on how they are set up for the class, will turn on if another student mic is also live.

 When the student is finished speaking, they will turn their own microphone off (by pushing their button again).


Discovery Commons has a small video recording studio location available to the Faculty of Medicine for educational projects. High-definition cameras, professional lighting, green screen, microphones, and teleprompter are some of the available resources.

Green screen studio

The studio is used for lecture recordings, interviews, and live webcasts.


A device used primarily in the studio that allows a presenter to look into a camera and see text or their presentation at the same time.


See Terrance Donnelly Health Sciences Centre

Terrance Donnelly Health Sciences Centre

Two of the four large lectures rooms used by the MD Program are in this building located at University of Toronto Mississauga campus; the other two are in the Medical Sciences Building at the St. George campus in Toronto. Also known as the HSC, it was built in 2011 and houses the Mississauga Academy of Medicine.

Videoconference (web) (aka webconference)

Technology that allows participants to see and hear each other via video in real time. Examples of web videconference tools are Zoom, Teams, and Skype.

Video Editing

The process of cutting and reordering video to remove unwanted video, add footage, and to add titles, logos, sound effects, and music.

Video Production

Recording an event or scripted program using video camera(s), lighting and sound equipment. Videos can be recorded in a studio or in the field and can include a wide variety of variables depending on script requirements and budget.


A live media presentation that is also distributed synchronously online to viewers over the internet via a streaming service. A one-to-many form of communication, participants can see and hear the event, but cannot be heard or seen; they often have the option of communicating to the event moderator and other participants via an integrated chat function. Discovery Commons has HD webcasting devices for live events. While webcasting, the event can also be recorded for later viewing on demand.

Wireless Microphone

Microphone that does not need a cable to transmit sound, and instead uses radio signals. Wireless microphones have the advantage that no cables get in the way of the presenter and avoid any trip hazards, but they require frequent battery refreshes for optimal sound. 

Wireless Handheld Microphone

The MD Program has several wireless handheld microphones, available at both the downtown and Mississauga sites, that are used primarily when panels of speakers are present at the front of the large lecture rooms used by the MD Program.

Wireless Lapel Microphone

A microphone that can be attached to the speaker's lapel or shirt front, and does not need a cable to transmit sound. One of these is at the teaching station in each of the large lectures rooms used by the MD Porgram. Teachers who leave the teaching station anytime during their presentation must wear the wireless lapel microphone in order that any remote students can hear them at all times. 

Zoom meetings/ Zoom webinars

Zoom meetings are usually used when all participants are expected or have the ability to participate equally: depending on the way the Zoom meeting is configured, participants can turn their mics and cameras on and can share their content. Breakout rooms are possible in Zoom meetings, and Zoom meetings are available with the Basic Zoom license. Zoom account pricing is based on number of meeting participants; eg, up to 100, 300, 500, and 1000.

Zoom webinars are usually used when the format of the session is one-to-many; ie, one or more presenters will do most of the talking and sharing of their content and the audience is neither heard nor seen. Audience participation is usually limited to chat and asking questions via a Q & A tool. Webinars are an add-on to Zoom licenses, with pricing based on the number of webinar attendees from 500 to 10,000.