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

# Use roles in prompts

> Structure prompts using role-based messages with system, user, assistant, and tool roles

Every prompt in Adaline is built from messages. The Editor provides a structured, role-based interface for composing these messages — giving you precise control over how the model interprets your instructions.

## Roles and content blocks

Each message has two components:

1. **Role** — Specifies who is speaking in the conversation.
2. **Content block** — Contains the actual text, images, or other content.

![Message structure showing roles and content blocks](https://mintcdn.com/adaline/-Bsa4BuK4fSdmy67/images/iterate/message-structure.png?fit=max\&auto=format\&n=-Bsa4BuK4fSdmy67\&q=85\&s=f5800ecad056a38de2e2d59ca0366b41)

Choose from the following roles:

| Role | Purpose |
| - | - |
| **System** | Sets the overall instructions, context, and behavioral guidelines for the model. |
| **User** | Represents end-user inputs — the questions or requests sent to the model. |
| **Assistant** | Defines the model's responses. Use this in [multi-shot prompts](https://www.adaline.ai/docs/iterate/multi-shot-prompting.md) to demonstrate expected output format. |
| **Tool** | Contains tool responses to tool calls. Used when building [prompts with tool interactions](https://www.adaline.ai/docs/iterate/use-tools-in-prompt.md). |

The **role** determines how the model treats the message, while the **content block** holds what is actually sent — whether that is [text](https://www.adaline.ai/docs/iterate/use-text-in-prompt.md), [images](https://www.adaline.ai/docs/iterate/use-images-in-prompt.md), [PDFs](https://www.adaline.ai/docs/iterate/use-pdfs-in-prompt.md), or a combination.

## Next steps

> [card] [Use Text in Prompts](https://www.adaline.ai/docs/iterate/use-text-in-prompt.md)
>
> Compose text content with variables, comments, and structured formatting.

> [card] [Use Images in Prompts](https://www.adaline.ai/docs/iterate/use-images-in-prompt.md)
>
> Add image inputs for multi-modal prompts.


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