> ## Documentation Index
> Fetch the complete documentation index at: https://docs.adgentek.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Glossary

> Terms used throughout the Adgentek documentation.

**Placement.** A registered position in your surface where Adgentek ads may render. Configured in the dashboard, referenced in your integration.

**Surface.** The environment where your users interact: a chat app, an AI search interface, an article page, or an agent runtime.

**Impression.** A verified, client-side render of an ad. Billable only when the impression pixel fires from a real browser or app context.

**Impression pixel.** A tracking URL included in the ad payload, fired as an image request from the client when the ad renders. The event that makes CPM demand billable.

**burl (billing notice URL).** A server-side notification fired on impression receipt. The only legitimate server-side tracking event in the Adgentek stack. A burl is a billing notice, not an impression; it does not qualify a surface for impression-priced demand.

**GIVT (general invalid traffic).** Traffic classified as invalid by verification vendors based on identifiable signatures, including requests originating from datacenter IP space. Impression events fired server-side are classified as GIVT and discarded. This is why impression tracking must be client-side.

**Demand tier.** One of the four sources in the waterfall: Direct, Programmatic, CPC, API/CPA. See [Demand sources](/publishers/concepts/demand-sources).

**Intent bucket.** One of nine classifications of the user's intent for the current turn, from Purchase to Entertainment. Determines demand eligibility and format selection. See [Intent classification](/publishers/concepts/intent-classification).

**Derived signal.** The privacy-safe data transmitted to demand partners: IAB categories, keywords, intent bucket, entity types. Raw prompts and transcripts are never derived signals.

**Engaged session.** A session where the user interacts with an ad unit at least once, for example tapping a chip in a Spark unit.

**Spark.** Adgentek's flagship conversational ad format: an interactive Q\&A unit where the user explores a brand's knowledge inside a single card. See [Ad formats](/publishers/concepts/ad-formats).