Reference

OTT glossary

90+ terms with crisp, cited definitions, aliases, and cross-references to deep-dive articles. From OTT, VOD, SVOD, AVOD, TVOD, and FAST to multi-DRM, CENC/CBCS, SSAI, SCTE-35, the encoding ladder, and QoE — every protection scheme, monetization model, delivery concept, and player acronym in one place. Search by name, filter by chapter, or jump straight to a letter.

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Egress

The cost of sending bytes out to viewers; the single biggest recurring expense in most OTT platforms.

E



EME (Encrypted Media Extensions)

The W3C browser API that wires a web player to a DRM system (the Content Decryption Module) for protected playback.

E



Encoding ladder

The set of quality variants (resolution plus bitrate) the player switches between as the network changes.

E

Engagement

How actively viewers use the service - frequency, depth, and breadth of viewing - and the precursor to retention.

E



Entitlement

The service that decides, for each viewer, exactly what they are allowed to watch right now — the hard part of billing.

E

EPG (electronic program guide)

The schedule grid that tells viewers what is playing now and next on each linear or FAST channel.

E

ExoPlayer (Media3)

Google's open-source, extensible media player for Android, now part of the Media3 library.

E



FairPlay

Apple's DRM system for Safari, iOS, and Apple TV; it requires the cbcs scheme of Common Encryption.

F



FAST (free ad-supported streaming TV)

Free, ad-supported channels that play a scheduled lineup like traditional TV, streamed over the internet.

F

Fill rate

The share of available ad slots that actually get filled with a paying ad.

F



Forensic watermarking

Embedding an invisible per-viewer identifier in the stream so a leaked copy can be traced back to the account.

F

Free trial

A limited period of free access used to convert prospects into paying subscribers.

F

Frequency capping

Limiting how many times a viewer sees the same ad, to avoid fatigue and wasted impressions.

F

GDPR

The EU's comprehensive data-protection law governing how personal data is collected and used.

G

Geo-blocking

Restricting where content can be watched, to honor territory-by-territory licensing rights.

G

Glass-to-glass latency

The total delay from the moment something happens in front of the camera to the moment a viewer sees it on screen.

G

GOP (group of pictures)

The repeating sequence of frames between keyframes; its length affects seeking, switching, and compression.

G

H.264 / AVC

The universal baseline video codec; less efficient than newer codecs but plays on virtually every device.

H

Hardware DRM

DRM whose keys and decryption live in a device's secure hardware; required for HD/4K premium content.

H

HDCP

Copy protection on the HDMI link between a device and a display; required by studios for high-value content.

H

HDR (high dynamic range)

Video with brighter highlights, deeper shadows, and wider color than standard SDR; a premium quality tier.

H

HEVC / H.265

A codec roughly twice as efficient as H.264, the practical choice for 4K and HDR, but with licensing complexity.

H



HLS

HTTP Live Streaming, Apple's segmented streaming protocol (IETF RFC 8216); the default for Apple devices.

H

hls.js

A popular open-source JavaScript library that plays HLS in browsers that lack native HLS support.

H



Ingest

The first stage of the pipeline, where source content (a file or a live feed) enters the platform for processing.

I

Keyframe (IDR frame)

A fully self-contained frame the player can start or switch on; the anchor points of a stream.

K



License server

The service that issues the decryption key and usage policy to an authorized player so it can play protected content.

L



Linear TV

A scheduled, channel-based lineup the viewer joins in progress, as opposed to picking a title on demand.

L



Live streaming

Encoding and delivering video in real time as an event happens, with a tight latency budget and no second chances.

L

LL-DASH (Low-Latency DASH)

The DASH approach to low-latency live, using chunked CMAF transfer to deliver media as it is produced.

L

LL-HLS (Low-Latency HLS)

Apple's extension to HLS that cuts live latency to a few seconds using partial segments.

L

LTV (lifetime value)

The total revenue a subscriber is expected to generate before they churn; bounds what you can spend to acquire them.

L



Manifest

The index file (HLS playlist or DASH MPD) that lists the available renditions and segments so the player can stream them.

M

Metadata

The structured descriptive data about each title that powers search, discovery, and recommendations.

M



Mezzanine

A high-quality intermediate copy of the source, the master from which all delivery renditions are encoded.

M



MSE (Media Source Extensions)

The W3C browser API that lets JavaScript feed media segments to the video element, enabling adaptive web playback.

M



Multi-CDN

Using two or more CDNs together and switching between them for resilience, regional coverage, and better pricing.

M



Multi-DRM

Protecting content once and issuing licenses across Widevine, PlayReady, and FairPlay so every device can play it.

M



Offline playback

Downloading protected content for viewing without a connection, governed by an offline DRM license with its own rules.

O