Viostream Glossary

An A-Z on terminology used in video streaming!


Viostream customers are segregated into unique accounts containing all of the Users for your company. Accounts may be further organized into Subaccounts which contain Media, Channels, Players and Sites.

Adaptive Bitrate

A video stream that allows the viewer to increase or decrease the video quality based on their local network conditions. With a fast internet connection, high quality video is delivered. With lower speed or patch connections, a lower quality version can be delivered in order to reduce or avoid buffering.

API Embed

A method of inserting a Viostream Player onto a website using the Viostream Player API. This method is recommended for advanced users and developers.


A credential used to access the Viostream REST API.

Aspect Ratio

The ratio of width to height for a video frame. Common aspect rations include 16:9 (modern landscape video), 4:3 (older landscape video), 1:1 (square) and 9:16 (portrait).


The amount of video data consumed by the viewers of your content. Measured in Gibibytes (GiB).


Load time for individual video chunks, which can cause viewer annoyance if adaptive bitrate streaming is not used (e.g. when serving an mp4 from a CMS such as Wordpress).


A Channel consists of a number of videos which can be collectively embedded in a particular order on a web site or Viostream Site as a single playlist. Media may be added to a Channel without modifying the embed code, enabling content managers to update their Channels without modifying the surrounding web pages.


A Chapter is a pre-defined point in a video to which viewers can easily navigate using the controls in the Viostream Player.


An algorithm used to encode and compress video or audio in digital form.


A format that stores video and audio metadata alongside the actual video and audio data (encoded according to a codec).

Content Delivery Network

A content delivery network (CDN) is a global network of edge servers that rapidly delivers content to end users.

Content Management System

A content management system (CMS) is a publishing tool that allows non-technical users to manage and update content, such as a website or blog. Viostream allows you to embed videos within a CMS using script or iframe embeds.


Cascading Style Sheets (CSS) are a style sheet language used to describe the presentation of an HTML document.


Reading audio and video streams from a container.

Domain Restriction

A form of content security that prevents a Player from loading unless it is embedded on specific domains.


A method of inserting a Viostream Player onto an external website. Viostream supports three types of embeds: script, iframe and API.


The process of cryptographically securing data in such a way that only authorized parties can read it.

Extended M3U

A file format for a multimedia playlist. Used by the Viostream Player to deliver adaptive bitrate video.

Frame Rate

The number of frames per second at which a video is recorded and displayed.


A form of content security that prevents a Player from loading unless the viewer is in a certain country or countries.


A Gibibyte (GiB), sometimes called a gigabyte (GB), is the unit measure of storage and bandwidth used by Viostream, and is equal to 230 (1,073,741,824)Z bytes.

H.264 Format

A file format used to deliver video over the Internet (also known as MPEG-4 AVC (Advanced Video Coding)). H.264 is used by Viostream and offers an optimum balance between quality and compression.


HTTP Live Streaming (HLS), an open specification for HTTP-based adaptive bitrate streaming developed by Apple. HLS breaks video into a sequence of small chunks 2-10 seconds in length. An extended M3U playlist file is used by the Player to select the most appropriate stream quality and download the chunks for playback.


HyperText Markup Language (HTML) is the language used to create web pages.

Iframe Embed

A method of inserting the Viostream Player onto a web page. This is usually used as a fallback for systems which do not support script embeds. For more information on using script embeds, please see our help article on embedding media.


A scripting language used to control content in a web browser.


JPEG (named after the Joint Photographic Experts Group) is a method used to compress images. Viostream uses this format to create thumbnails for videos.


A method of displaying video on a screen with a different aspect ratio by leaving a black space above and below the image. This is commonly used when widescreen video is displayed on a narrower screen. See also Pillarbox.


The collection of Media Assets in your Viostream account.

Live Streaming

A protocol for streaming video of an event as it happens, by transcoding video streams on the fly and delivering them directly to the Player.

A graphical image that represents a company or product.

Media Asset

An individual video or audio asset that can be managed and shared from your Viostream account.


The title, description, tags, and all other information related to an individual Media Asset.


Writing audio and video streams into a container.


OAuth is an open standard providing secure delegated access to systems. Viostream supports the use of OAuth 2.0 in order to provide a Single Sign On experience for users.


An Overlay is a feature that prompts viewers to click on a link at certain pre-set points of a video. Commonly used to drive clicks through to a landing page, survey or other external website.


A method of displaying video on a screen with a different aspect ratio by leaving a black space to the left and right of the image. This is commonly used when 4:3 video is displayed on a wide screen. See also Letterbox.


The playing of video or audio in a Viostream Player.

Public Key

Every Media Asset in Viostream has a unique public key that is used to embed and share the video. This public key will never change, even if you upload a new version of the video, enabling you to share your video in many places and easily manage it in a single location.


With adaptive bitrate streaming, multiple versions of the same video are created. Each version of the video is called a rendition, and has a specified bit rate and resolution. During playback, the Viostream Player optimizes viewer experience by selecting the highest quality rendition that the viewer’s connection and device will support.

Reference ID

The reference ID is a piece of metadata which can be used to assign an external identifier to a Media Asset in Viostream. This enables developers to build seamless integrations between Viostream and third party systems, such as a CMS.


Security Assertion Markup Language is an open standard used to authenticate users to third party systems. Viostream customers can use SAML to provide a single sign-on experience for their staff, as well as controlling login access to Viostream Sites.

Script Embed

A method of inserting the Viostream Player onto a web page. For more information on using script embeds, please see our help article on embedding media.

Single Sign-On

Single sign-on (SSO) is a system of authentication that allows users to log in to many systems via a single set of credentials. Implementing SSO increases security and reduces complexity for network and systems administrators, and can easily be achieved with Viostream.


Tags are a free-form tool for organizing content. These can be helpful for sorting videos by department, genre, speaker and more.


A Theme is a customizable page that you can use to brand and share your videos.


An image that is displayed in the Player before playback commences.


Converting a raw video file (e.g. mp4) into an adaptive bitrate stream.

Viostream Player

The Viostream Player is a modern video player that allows you to embed video across all of your internal and external facing platforms. For more information on the features of the Viostream Player, please see the relevant help article.


A watermark is an image that can be burned into you videos at the time of transcoding.


Web Video Text Tracks (WebVTT) is a file format used to deliver captions. Viostream automatically generates these files when your videos are ingested, and they can be edited using the in-platform caption editor.

Related Docs

Getting Started
Your Library
Managing Media
Embedding Your Media
Media Players
Managing Your Account
Managing Events
Technical Information