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

# Block Types

> Building the Logic and Actions for Each Step in Your Conversation 

[**Blocks**](https://api.vapi.ai/api#/Blocks/BlockController_create) are the functional units within a Step, defining what action happens at each stage of a conversation. Each Step can contain only one Block, and there are three main types of Blocks, each designed to handle different aspects of conversation flow.

<Note>
  Blocks is currently in beta. We're excited to have you try this new feature and welcome your [feedback](https://discord.com/invite/pUFNcf2WmH) as we continue to refine and improve the experience.
</Note>

#### Types

* [**Conversation:**](\(https://api.vapi.ai/api#:~:text=ConversationBlock\)) This block type manages interactions between the assistant and the user. A conversation block is used when the assistant needs to ask the user for specific information, such as contact details or preferences.
* [**Tool-call:**](https://api.vapi.ai/api#:~:text=ToolCallBlock) This block allows the assistant to make external tool calls.
* [**Workflow:**](https://api.vapi.ai/api#:~:text=WorkflowBlock) This block type enables the creation of subflows, which are smaller sets of steps executed within a Block. It can contain an array of steps (`steps[]`) and uses an `inputSchema` to define the data needed to initiate the workflow, along with an `outputSchema` to handle the data returned after completing the subflow. Workflow blocks are ideal for organizing complex processes or reusing workflows across different parts of the conversation.