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

# Core Concepts

> Key terms and concepts in A2

## Who is this guide for?

This guide is for anyone who wants to understand the core concepts in order to use A2 effectively. It explains key terms such as accounts, placements, campaigns, and allocations.

***

## Concept map

The core concepts in A2 are connected as follows.

```mermaid theme={null}
flowchart TD
    Account[Account] -->|Owns| Campaign[Campaign]
    Account -->|Owns| Placement[Placement]
    Campaign -->|Contains| Creative[Creative]
    Campaign -->|Requests| Allocation[Allocation]
    Allocation -->|Links to| Placement
    Placement -->|Displays| Creative
```

***

## Accounts and roles

A2 has three account types, each with different permissions and capabilities.

| Role | English | Description | Key permissions |
| - | - | - | - |
| Admin | Admin | Top-level permission that manages the entire platform | System settings, payment management, management of all accounts |
| Retailer | Retailer | A media owner that owns and sells placements | Create placements, approve/reject allocations, view revenue reports |
| Advertiser | Advertiser | A brand or seller that runs ads | Create campaigns, register creatives, request allocations |

### Admin

The top-level permission that manages the entire platform.

**What you can do:**

* Create and manage retailer and advertiser accounts
* Allocate budget to each account
* Configure system settings (payment integration, notifications, permissions, etc.)
* Monitor overall platform performance
* View activity logs

Admins can access all placements and campaigns. For small-scale operations, a single admin account can act as both retailer and advertiser.

### Retailer

A **media owner** that owns and provides ad placements such as shopping malls, communities, websites, and apps.

**What you can do:**

* Create and configure spaces for ads (placements)
* Build placement catalogs (bundle multiple placements together)
* Approve or reject allocation requests
* Connect external ad sources
* Analyze ad revenue per placement and in aggregate, and view reports

Retailers can access only the placements they own, and they directly control which ads appear on their services.

### Advertiser

A brand, product seller, or similar party that **runs** ads.

**What you can do:**

* Create and manage ad campaigns
* Upload and manage ad creatives (images, videos, etc.)
* Request allocations (request that ads appear on desired placements)
* Analyze campaign performance (ad impressions, clicks, sales, etc.)
* Configure targeting (define who sees the ads)

Advertisers can access only the campaigns and creatives they created. They run ads within their allocated budget.

***

## Placement

A placement is the **location** where an ad is displayed. It is an area a retailer designates on its service to show ads, saying "this is where ads will go."

### Placement examples

* Banner at the top of the main page
* Middle of a product listing page
* Top of search results
* Bottom of a product detail page
* Side area of the cart page

### Placement settings

| Setting | English | Description | Example |
| - | - | - | - |
| Creative type | Creative Type | Ad formats to allow | Display, video, native |
| Size | Size | Pixel size of the ad area | 1200×120, 300×250 |
| Approval mode | Approval Mode | How allocation requests are handled | Manual approval, auto approval |
| Floor price | Floor Price | Minimum price for an ad impression | CPM of 1,000 KRW or more |

→ Learn more: [Placement guide](/guides/for-retailers/en/placement)

### Placement Catalog

A unit for bundling multiple placements into a single product to sell to and manage for advertisers. It is useful when offering placements to advertisers as a package.

Example: a "main banner + middle of product listing + bottom of detail page" package

→ Learn more: [Placement Catalog guide](/guides/for-retailers/en/placement-catalog)

***

## Campaign

A campaign is the **unit** of advertising activity. It is an ad project an advertiser creates to achieve a specific goal.

A campaign defines "to whom (Targeting)", "what (Creative)", and "how much (Budget)" to show.

### Campaign examples

* Summer new-arrivals promotion
* Brand awareness campaign
* Seasonal sale event
* Promotion for a newly onboarded brand

### Campaign settings

**Goal**: Select the main purpose of the campaign. The billing model depends on the goal.

| Goal | Billing model | Best for |
| - | - | - |
| Impressions | CPM (per 1,000 impressions) | Increasing brand awareness |
| Clicks | CPC (per click) | Driving site traffic |
| Conversions | CPA (per conversion) | Driving purchases, sign-ups |

**Budget**: The total amount to spend on this campaign. Ads stop serving once the budget is exhausted.

**Period**: The campaign start and end dates. Ads are not served outside this period.

**Targeting**: Set conditions for which users see the ads.

* User attributes (age, gender, etc.)
* Behavior-based (recently viewed products, past purchase history, etc.)
* Time of day (serve only on specific days or hours, etc.)

→ Learn more: [Campaign settings guide](/guides/for-advertisers/en/campaign-budget)

***

## Creative

A creative is the actual **ad content** that is displayed: the images, videos, text, and so on that users see.

### Creative examples

<Tabs>
  <Tab title="Display (banner)">
    | Item | Specification |
    | - | - |
    | Format | Image (JPG, PNG, GIF) |
    | Max file size | 500KB |
    | Required elements | Image, click URL |
    | Characteristics | The most common ad format |
  </Tab>

  <Tab title="Video">
    | Item | Specification |
    | - | - |
    | Format | MP4 |
    | Max file size | 10MB |
    | Required elements | Video file, click URL |
    | Characteristics | High attention, well suited to storytelling |
  </Tab>

  <Tab title="Native">
    | Item | Specification |
    | - | - |
    | Format | Image + text combination |
    | Max file size | Image 500KB |
    | Required elements | Image, title, description, click URL |
    | Characteristics | Blends naturally with the content |
  </Tab>
</Tabs>

### Creative status

```mermaid theme={null}
flowchart LR
    A[Draft] --> B[Pending review]
    B --> C{Approved?}
    C -->|Approve| D[Active]
    C -->|Reject| E[Needs changes]
    E --> A
    D --> F[Inactive]
    F --> D
```

| Status | English | Description |
| - | - | - |
| Draft | Draft | Creative being written |
| Pending review | Pending | Waiting for admin approval |
| Active | Active | Approved and currently serving |
| Inactive | Inactive | Serving stopped |

You can register multiple creatives in a single campaign. A2 analyzes performance data and automatically prioritizes the creatives predicted to perform better.

→ Learn more: [Creative types guide](/guides/for-advertisers/en/creative-types)

***

## Allocation

An allocation **links** a campaign to a placement. It is the setting that says "show this campaign's ads on that placement."

### Allocation process

```mermaid theme={null}
flowchart LR
    A[Advertiser: Allocation request] --> B[Retailer: Review]
    B --> C{Approved?}
    C -->|Approve| D[Ads start serving]
    C -->|Reject| E[Returned with reason]
```

1. **Request**: The advertiser requests that a campaign be allocated to the desired placement.
2. **Review**: The retailer checks the creatives and campaign details.
3. **Approve/Reject**: The retailer approves or rejects the allocation.
4. **Serve**: Ads for an approved allocation start serving immediately.

### Allocation status

| Status | English | Description |
| - | - | - |
| Requested | Requested | Requested by the advertiser; under retailer review |
| Approved | Approved | Approved by the retailer; ads are serving |
| Rejected | Rejected | Rejected by the retailer (reason available) |
| Paused | Paused | Serving temporarily stopped |

### Allocation settings

| Setting | English | Description |
| - | - | - |
| Priority | Priority | Determines serving order when multiple campaigns share a placement |
| Frequency cap | Frequency Cap | Maximum number of times an ad is shown to the same user |
| Period | Period | Start/end dates of the allocation itself (separate from the campaign period) |

→ Learn more: [Allocation request guide](/guides/for-advertisers/en/allocation-request), [Allocation review guide](/guides/for-retailers/en/allocation-review)

***

## Metrics

Key metrics for measuring ad performance.

| Metric | English | Description | Formula |
| - | - | - | - |
| Impressions | Impressions | Number of times the ad was shown on screen | - |
| Clicks | Clicks | Number of times users clicked the ad | - |
| CTR | CTR (Click-Through Rate) | Ratio of clicks to impressions | Clicks / Impressions × 100 |
| CPM | CPM (Cost Per Mille) | Cost per 1,000 impressions | Cost / Impressions × 1,000 |
| CPC | CPC (Cost Per Click) | Cost per click | Cost / Clicks |
| ROAS | ROAS (Return on Ad Spend) | Revenue return relative to ad spend | Revenue / Ad spend × 100 |


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