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

# What Is a PAL?

> A short definition of PAL, how it relates to Face and Conversation, and where to configure one.

A **PAL** (Personified Application Layer) is the behavior configuration for your AI agent in Conversational Video Interface (CVI). It defines how the agent thinks, speaks, and acts during a conversation.

The **Face** is separate: it is the on-screen likeness and default voice. A **Conversation** is the live session that puts a PAL and a Face together over WebRTC.

| Piece            | What it is                                              | What you configure                                                                   |
| ---------------- | ------------------------------------------------------- | ------------------------------------------------------------------------------------ |
| **PAL**          | Behavior, knowledge, tools, skills, and pipeline layers | System prompt, objectives, guardrails, LLM, perception, TTS overrides, tools, skills |
| **Face**         | Visual appearance and default voice                     | Stock face or a trained face                                                         |
| **Conversation** | One live call                                           | Which PAL and Face join, plus session options                                        |

## Why the name matters

Docs and the API use **PAL** for the behavior object and **Face** for visual appearance and voice. Older docs and some endpoints still say **persona** and **replica**. Same ideas: PAL owns prompts, layers, tools, and skills; Face is the on-screen likeness and voice.

Prefer **PAL** and **Face** in new work. Legacy names still work on existing endpoints and request fields (`/v2/personas`, `/v2/replicas`, `persona_id`, `replica_id`, and related aliases) for backward compatibility.

## Where to go next

* [PAL Overview](/sections/conversational-video-interface/pal/overview) - fields, layers, and customization options
* [What Is CVI?](/sections/conversational-video-interface/overview-cvi) - how PAL, Face, and Conversation fit in the full pipeline
* [CVI Quickstart](/sections/conversational-video-interface/quickstart/cvi-quickstart) - create a PAL and start a conversation