A working reference for the people building, running, and growing streaming services, covering delivery, content processing, monetisation, security, UX, and business metrics.
The Leyra Team
Running a streaming service means working across a wide mix of technical, commercial and operational language. Some terms come from broadcast. Others from SaaS, ad tech, video engineering, content delivery, security, UX, analytics and subscriber management. Together, they create a vocabulary that spans several disciplines and is not always explained in one place.
This glossary brings those terms together in a practical reference for the teams building, running and growing OTT services. It covers the language that comes up most often in platform decisions, vendor conversations, internal reporting and day-to-day operations.
Rather than organising terms alphabetically, we’ve grouped them by area so related concepts sit together and are easier to understand in context.
Jump to a section:
Delivery and playback
Content processing
Security and rights
Monetisation and advertising
Billing, access, and subscriber management
User experience and front-end
Quality and performance monitoring
Business metrics and success indicators
Delivery and playback
OTT — Over-the-Top
Video delivered over the internet, bypassing traditional cable or satellite infrastructure. It’s the technology behind services like Netflix and Disney+, as well as the growing number of specialised streaming platforms serving specific audiences. Leyra is an end-to-end OTT platform that supports the full service, from apps and content management to monetisation, subscriber management, and ongoing growth.
CDN — Content Delivery Network
A distributed network of servers that cache and deliver content based on the viewer's location, reducing latency and buffering. CDN performance is one of the more direct variables in playback quality.
Edge server
Part of the CDN, these are servers positioned as close as possible to the viewer. They handle the final leg of delivery and are what makes geographically distributed audiences feel like they are watching from the same location as the origin.
Origin server
Where the master copy of your content lives before it is distributed across the CDN. The origin is not where most viewers pull from — that load is absorbed by the CDN — but its reliability still matters.
DASH — Dynamic Adaptive Streaming over HTTP
A streaming method that adjusts video quality in real time based on available network bandwidth. Works on the same principle as ABR (Adaptive Bitrate Streaming), and is widely used alongside HLS (HTTP Live Streaming).
ABR — Adaptive Bitrate Streaming
Automatically adjusts video resolution and quality based on the viewer's current bandwidth. ABR is what allows a stream to continue playing smoothly when network conditions change rather than stalling entirely.
HLS — HTTP Live Streaming
An adaptive bitrate protocol developed by Apple that segments the video stream into small chunks for more reliable delivery. HLS has become a de facto standard across most device types.
Latency
The delay between an event occurring and a viewer seeing it. For live content, particularly sports streaming, managing latency is one of the more technically demanding requirements. For VOD, it matters mainly at the point of pressing play.
Buffering
The temporary pause in playback caused by the player waiting for data to arrive. Usually a symptom of insufficient bandwidth, CDN delivery issues, or misconfigured ABR logic.
CMAF — Common Media Application Format
A standardised format that simplifies how streaming media is packaged and delivered across different devices and protocols. CMAF reduces the need to maintain separate content versions for different playback environments.
Content processing
Transcoding
Converting a video from one format or resolution to another to ensure it can play across different devices and network conditions. A single piece of source content typically needs to be transcoded into multiple renditions before delivery.
Encoding
Compressing raw video data into a format suitable for storage and streaming. Encoding is closely related to transcoding, but refers specifically to the initial conversion from raw or high-quality source files into a deliverable format.
Codec
The software or standard that handles compression and decompression of video or audio. H.264 remains widely used; H.265 offers better compression at the cost of higher processing overhead; AV1 is increasingly adopted for streaming due to its efficiency.
Bitrate
The volume of data transferred per second in a video stream. Higher bitrates carry more detail and produce better picture quality, but require more bandwidth. Bitrate ladders — the set of bitrate/resolution combinations you offer — have a direct effect on both quality and infrastructure cost.
Frame rate
The number of frames displayed per second. Standard video typically runs at 25fps or 30fps; higher frame rates (60fps, 120fps) are used for sports and gaming content where motion clarity matters.
HDR — High Dynamic Range
A video standard that expands the contrast ratio and colour range available in a video image. HDR content looks noticeably different on capable displays, with more detail in both bright and dark areas.
SDR — Standard Dynamic Range
The traditional video standard that HDR replaces or supplements. SDR is still the most commonly consumed format given device coverage, but HDR-capable content is increasingly expected by premium audiences.
Resolution
The number of pixels in a video image — 720p, 1080p, 4K. Higher resolution means more detail, but also larger file sizes and higher bandwidth requirements. Delivering the right resolution for the device and connection is what ABR handles.
Rendition
A single version of a piece of content at a specific resolution and bitrate, used within an adaptive bitrate stream. A typical encoding pipeline produces a ladder of renditions so the player can switch between them as conditions change.
VMAF — Video Multi-Method Assessment Fusion
A video quality metric developed by Netflix that combines several measurement methods to model how a human viewer perceives quality. More reliable than simple technical measures like PSNR for assessing real-world playback experience.
Security and rights
DRM — Digital Rights Management
Technology used to control how digital content is accessed, copied, and distributed. Common DRM systems include Widevine (Google), FairPlay (Apple), and PlayReady (Microsoft). Managing DRM across devices requires either a multi-DRM solution or per-platform implementation.
Tokenisation
The use of time-limited, encrypted access tokens to authenticate and authorise video stream requests. Tokenisation is a standard mechanism for ensuring that only entitled users can access a given stream, and that shared or scraped URLs expire quickly.
Geo-blocking
Restricting content availability based on the viewer's geographic location, usually to comply with territorial licensing agreements. For services with international rights, geo-blocking is a routine operational requirement.
Monetisation and advertising
SVOD / AVOD / TVOD
The three primary video monetisation models. SVOD (Subscription Video on Demand) charges a recurring fee for access. AVOD (Advertising Video on Demand) is free to viewers, funded by advertising. TVOD (Transactional Video on Demand) charges per title or rental. Many platforms now operate hybrid models combining two or more of these. Leyra's monetisation and billing capabilities are built to support all three models, and combinations of them.
HVOD — Hybrid Video on Demand
A monetisation model that combines subscription and ad-supported tiers, allowing platforms to serve different segments of their audience with different pricing and access arrangements.
VOD — Video on Demand
Content that users can watch at any time, as opposed to scheduled linear broadcast. Most streaming services are built primarily around VOD, though many also carry live or scheduled content.
PPV — Pay-Per-View
A model where viewers pay a one-time fee for access to a specific event or title, most commonly used for live sports or entertainment events.
EST — Electronic Sell-Through
A model where viewers purchase a permanent digital copy of a title. Common in transactional stores alongside rental options.
DAI — Dynamic Ad Insertion
Real-time insertion of video advertisements into a stream, targeted to the individual viewer rather than broadcast as a single ad feed. DAI is what makes it possible to serve different ads to different viewers watching the same content.
CSAI — Client-Side Ad Insertion
Ads are requested and inserted by the viewer's own device during playback. CSAI is more vulnerable to ad blockers than SSAI and can introduce visible load pauses between content and ad.
SSAI — Server-Side Ad Insertion
Ads are stitched into the video stream before it is delivered, so the viewer's player receives a single uninterrupted stream. SSAI produces a smoother viewing experience and is harder to block, though it adds complexity to ad reporting and measurement.
SSP — Supply-Side Platform
A platform that allows publishers and streaming operators to manage and sell their video advertising inventory programmatically.
DSP — Demand-Side Platform
Used by advertisers and agencies to buy video ad space across multiple publishers through automated bidding.
DMP — Data Management Platform
Collects and organises audience data to support ad targeting. Being replaced in many contexts by CDPs (Customer Data Platforms), which are better suited to first-party data strategies.
CPM — Cost Per Mille
The cost charged per 1,000 ad impressions. A standard pricing unit in programmatic advertising.
IAB — Interactive Advertising Bureau
An industry body that sets standards for digital advertising, including the VAST and VMAP specifications that govern how video ads are served.
CMP — Consent Management Platform
Manages user permissions and privacy preferences to support compliance with GDPR, CCPA, and similar regulations. A requirement for any service using targeted advertising or third-party tracking.
TCF — Transparency and Consent Framework
An IAB standard for communicating and recording user consent in digital advertising. Used to pass consent signals between CMPs and ad tech vendors.
IFA — Identifier for Advertisers
A device-level identifier used for ad tracking and frequency capping. Increasingly constrained by platform-level privacy controls.
VAST — Video Ad Serving Template
A specification that defines how video ad servers communicate with video players. VAST is the standard format for delivering pre-roll, mid-roll, and post-roll advertising.
VMAP — Video Multiple Ad Playlist
An extension of VAST that defines when ad breaks should appear in a video — including positions, timing, and pod structure.
VPAID — Video Player-Ad Interface Definition
An older standard for interactive video ads that is being phased out due to security vulnerabilities and inconsistent implementation across players.
SIMID — Secure Interactive Media Interface Definition
The replacement for VPAID, providing a more secure and standardised framework for interactive video advertising.
ADR — Average Daily Revenue
Average revenue generated per day. Useful for short-term performance tracking and forecasting seasonal patterns.
MAU / DAU — Monthly Active Users / Daily Active Users
Standard engagement metrics. The ratio of DAU to MAU (sometimes called the "stickiness ratio") indicates how frequently active users return within a month.
ARPU — Average Revenue Per User
Total revenue divided by the number of active users over a period. One of the more useful high-level metrics for tracking whether monetisation efficiency is improving.
Billing, access, and subscriber management
CRM — Customer Relationship Management
A system for managing subscriber data, interactions, and communication history. In a streaming context, CRM underpins retention campaigns, support workflows, and subscriber segmentation. For more on how segmentation tools work in practice, see how OTT segmentation tools can close the gap between insight and experience.
CMS — Content Management System
Handles the organisation, metadata, categorisation, and publishing of video content. A well-configured CMS reduces operational overhead around content operations significantly. See how Leyra approaches content management.
Entitlement system
Controls which content a given user can access based on their subscription tier, purchase history, or other access rules. Entitlement logic can become complex quickly when a service operates multiple tiers, bundles, or regional variations.
Billing engine
Processes payments, manages recurring charges, handles refunds and retries, and produces invoicing. Billing reliability has a direct effect on both revenue and subscriber experience.
SMS — Subscriber Management System
Manages authentication, account settings, and access permissions. Closely related to the entitlement system and often integrated with the billing engine.
Cloud DVR (cDVR)
Allows viewers to record live content and store it in the cloud for later playback. Requires careful rights management to ensure recordings comply with licensing agreements.
nPVR — Network Personal Video Recorder
A server-based recording system that enables viewers to record programmes without any local hardware. Functionally similar to cloud DVR; the terminology tends to vary by region and provider.
User experience and front-end
UI / UX — User Interface / User Experience
UI refers to the design and layout of the service — navigation, visual hierarchy, component design. UX refers to the overall experience of using the service — how easy it is to find content, complete a sign-up, or return after a gap. Both matter significantly for engagement and retention. Leyra's streaming apps are built with this in mind across every major device and platform.
EPG — Electronic Programme Guide
A navigable schedule of available or upcoming content, most commonly used in linear or live TV contexts. EPG design has a direct impact on content discovery for live-focused services.
CTA — Call to Action
An interface prompt designed to drive a specific user action — subscribing, starting a free trial, watching a trailer, or upgrading a plan. CTA placement and wording are among the more frequently tested variables in conversion optimisation.
SEO — Search Engine Optimisation
For streaming services, SEO applies to both the platform website and, where relevant, publicly accessible content pages. Metadata quality, page structure, and site speed all contribute to organic search performance.
Play rate
The percentage of visitors to a video page who actually click play. Low play rates on content pages often indicate a mismatch between discovery and intent, or a problem with thumbnail and metadata presentation.
Quality and performance monitoring
QoS — Quality of Service
A technical measure of delivery performance, covering metrics like uptime, error rates, and delivery speed. QoS is primarily an infrastructure and engineering concern.
QoE — Quality of Experience
How the viewer perceives the quality of their playback experience, including resolution, buffering frequency, and responsiveness. QoE is what QoS ultimately affects, and the two do not always move in the same direction.
Engagement rate
The frequency and depth of viewer interaction with content. Definitions vary, but typically covers some combination of sessions, time watched, and actions taken (shares, saves, ratings).
Average watch time
The average duration viewers spend on a given piece of content. Short average watch times on long-form content can indicate problems with content quality, discovery mismatch, or UX friction early in playback.
Completion rate
The percentage of viewers who watch a piece of content from start to finish. A useful signal for content performance and, in combination with average watch time, can help distinguish between editorial issues and delivery problems.
Buffering ratio
The proportion of total watch time spent buffering rather than playing. High buffering ratios correlate with significantly elevated churn risk; even short buffering events affect perceived quality.
Peak concurrent users
The maximum number of viewers simultaneously streaming on your platform at a given point. Planning for peak load — particularly around live events — is one of the more consequential infrastructure decisions a streaming service makes.
Business metrics and success indicators
NPS — Net Promoter Score
A measure of customer loyalty based on the likelihood of viewers recommending the service to others. NPS is a useful directional signal but needs to be read alongside behavioural data rather than in isolation.
CAC — Customer Acquisition Cost
The total cost of acquiring a single paying subscriber, including marketing, sales, and promotional spend. CAC is most useful when tracked alongside CLTV (Customer Lifetime Value) to understand whether acquisition economics are sustainable.
CLTV — Customer Lifetime Value
The total revenue expected from a subscriber over the duration of their relationship with the service. CLTV depends heavily on churn rate, and improving retention typically has a larger effect on CLTV than improving acquisition.
Churn rate
The percentage of subscribers who cancel their service within a given period. Monthly churn compounds quickly — even a modest reduction has a significant long-term effect on subscriber base and revenue. Reducing churn is almost always more cost-effective than replacing churned subscribers through acquisition. For a deeper look at why churn tends to rise after launch, see why streaming services stall after launch.
MRR / ARR — Monthly Recurring Revenue / Annual Recurring Revenue
The predictable, repeating revenue generated by active subscriptions. MRR is useful for month-to-month performance tracking; ARR provides a longer-term view and is more commonly used for investor and board reporting.
A note on putting these terms to use
Understanding the vocabulary is a useful starting point. The real value comes when teams can connect those terms, metrics and workflows to the decisions they need to make every day. For streaming operators, that means having a clear view across delivery, content, subscribers and monetisation, so teams can spot what is happening, understand why it matters, and act quickly.
That is what Leyra is built to support. The platform brings together the operational layers of a streaming service, including apps, content management, monetisation and subscriber operations, as one connected system rather than a collection of separate tools. Teams can see what is happening across the service without having to piece together data from multiple sources. They can make changes to pricing, content, campaigns or UX without the usual overhead that slows iteration down.
And when requirements evolve, Leyra’s open marketplace makes it possible to extend the platform with specialist tools and partners, without having to rebuild around every new addition.
If you are evaluating your options or want to understand what Leyra could do for your service, book a demo.
