Key Terms & Glossary

A reference for supply sources (Publishers), demand sources (DSPs), and business stakeholders who want to understand the language of programmatic advertising.

A

Ad Exchange A technology platform that connects supply sources (supply) with advertisers and demand sources (demand) through automated real-time auctions. Praevis is an ad exchange.

App-ads.txt An IAB standard text file that supply sources host on their developer domain to declare which ad exchanges are authorised to sell their inventory. Prevents domain spoofing. → Setup guide

Auction The automated process where multiple demand sources submit bids for a single ad impression, the highest valid bid wins, and the creative is served. On Praevis: first-price, under 10ms.

B

Bid Floor The minimum price a demand source must bid to be eligible to win an impression. Set per supply source. Bids below the floor are ignored.

Bid Request A structured JSON message (OpenRTB format) that an exchange sends to demand sources describing an available ad impression — who’s watching, what device, where, what content.

Bid Response The demand source’s reply to a bid request. Contains the price they’re willing to pay and the creative (VAST URL or banner) to serve if they win.

C

Circuit Breaker A safety mechanism that pauses bid requests to a demand source endpoint when it exceeds a timeout or error threshold. Automatically resets after 60 seconds. → Details

Clearing Price The final price paid for an impression in a first-price auction. Equal to the winning bid. No second-price reduction on Praevis.

CPM (Cost Per Mille) The price for 1,000 ad impressions, in USD. Example: $3.00 CPM = $0.003 per impression.

CTV (Connected TV) Television content viewed on an internet-connected screen — smart TVs, streaming sticks (Roku, Fire TV), game consoles. High-value inventory on Praevis.

D

Delegate Praevis’s co-located bidding engine. Demand sources define bidding logic as JSON strategy rules; the engine evaluates them inside Praevis infrastructure in under 1ms. → Guide

Demand source (Demand-Side Platform) A platform used by advertisers and agencies to buy ad inventory programmatically. Demand sources connect to exchanges, receive bid requests, and submit bids in real time.

Deal ID A private identifier shared between a supply source and specific demand sources for preferred-access or guaranteed inventory deals (Private Marketplace / PMP).

E

eCPM (Effective CPM) Calculated revenue per 1,000 impressions: (revenue / impressions) × 1,000. Used to compare revenue across publishers and time periods with different impression volumes.

F

Fill Rate The percentage of auction requests that result in a filled ad impression. Fill Rate = filled impressions / total ad requests. Low fill rate indicates floor price issues, pool mismatches, or insufficient demand sources.

Floor Price See Bid Floor.

G

GIVT (General Invalid Traffic) Invalid traffic that is identifiable through simple means — known bots, data centre IPs, crawlers. Defender’s hardest filter. → IVT details

Guide Praevis’s budget autopilot. Converts demand source daily budgets into QPS limits, pacing spend evenly across the day and across regions. → Guide details

I

Impression A single instance of an ad being served to a viewer. Revenue is earned per impression. An impression is counted when the creative is rendered (not just when an auction is won).

IVT (Invalid Traffic) Any ad request not generated by a real human — bots, scrapers, data centre traffic, and behavioural fraud. Praevis platform IVT rate: <2%.

M

MRAID (Mobile Rich Media Ad Interface Definitions) A standard API for rich media ads in mobile app environments. MRAID 3.0 supported on Praevis for mobile banner/interstitial.

O

OpenRTB The IAB standard protocol for real-time bidding. Defines the JSON format of bid requests and responses. Praevis uses OpenRTB 2.5.

P

Passback When no demand source wins an auction (empty VAST), the supply source’s ad server serves a fallback ad (house ad or another demand source). Supply sources configure passbacks in their ad server settings.

Pathfinder Praevis’s smart demand source routing system. Filters ineligible demand sources before an auction starts — reducing wasted bid requests and improving auction speed. → Pathfinder details

Pool A group of supply sources that demand sources can subscribe to for targeting. Demand sources receive bid requests only from pools they’ve subscribed to. → Pool docs

P50 / P95 / P99 Latency Latency percentiles. P50 = median (50% of requests are faster). P95 = 95% of requests are faster. P99 = 99% of requests are faster. P99 is the “tail latency” — how bad slow cases are.

Q

QPS (Queries Per Second) The rate at which bid requests are sent to a demand source. Guide manages QPS to pace budget spending. Pathfinder enforces QPS limits set by Guide.

R

RPS (Requests Per Second) The rate of ad requests arriving at the exchange from supply sources. Displayed live on the dashboard.

RTB (Real-Time Bidding) The process of buying and selling ad impressions in real-time auctions conducted in milliseconds as a page loads or content streams.

S

SIVT (Sophisticated Invalid Traffic) Invalid traffic that requires more advanced analysis to detect — ad stacking, pixel stuffing, human-operated fraud. Harder to catch than GIVT. → IVT details

SSP (Supply-Side Platform) A platform used by supply sources to manage and sell their ad inventory programmatically. Praevis functions as an exchange that SSPs and direct supply sources connect to.

T

Timeout When a demand source endpoint doesn’t respond within the allowed window (150ms on Praevis), the bid is ignored and the auction proceeds without them. Repeated timeouts trigger the circuit breaker.

V

VAST (Video Ad Serving Template) The IAB standard XML format for video ads. Defines the creative URL, tracking pixels, click-through URLs, and duration. Praevis supports VAST 2.0–4.2.

VPAID (Video Player-Ad Interface Definition) An older standard for interactive video ads. Not supported on Praevis — use VAST 4.x with Verification nodes for viewability measurement instead.

W

Win Rate The percentage of bid requests that result in a won auction. Win Rate = wins / bid requests. Includes no-bids in the denominator. Typical range: 5–40% depending on demand source targeting and floor prices.