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

# ClickML Studio components reference

> Browse every drag-and-drop component available on the ClickML Studio canvas, including data readers, processors, models, and evaluation blocks.

Components are the building blocks of a pipeline. Each one takes an input, does one thing, and passes an output to the next component.

## How components connect

* **Output handle** — the dot on the right side of a component. Drag from here to connect.
* **Input handle** — the dot on the left side. Drop a connection here.
* Data flows left to right through the pipeline.
* Some components have multiple handles (e.g. Train-Test Split outputs separate `X Train`, `Y Train`, `X Test`, `Y Test` handles).

## Full component list

| Category            | Component              | Input                | Output     |
| ------------------- | ---------------------- | -------------------- | ---------- |
| Data                | CSV Reader             | —                    | DataFrame  |
| Data                | Excel Reader           | —                    | DataFrame  |
| Processing          | Data Cleaning          | DataFrame            | DataFrame  |
| Processing          | Missing Values         | DataFrame            | DataFrame  |
| Processing          | Scaling                | DataFrame            | DataFrame  |
| Processing          | Encoding               | DataFrame            | DataFrame  |
| Processing          | Data Transformation    | DataFrame            | DataFrame  |
| Processing          | Delete Columns / Rows  | DataFrame            | DataFrame  |
| Processing          | Train-Test Split       | DataFrame            | Split Data |
| Feature Engineering | Feature Extraction     | DataFrame            | DataFrame  |
| Feature Engineering | Feature Transformation | DataFrame            | DataFrame  |
| Feature Engineering | Feature Selection      | DataFrame            | DataFrame  |
| Wrangling           | Merge / Join           | 2× DataFrame         | DataFrame  |
| Wrangling           | Concatenate            | 2× DataFrame         | DataFrame  |
| Analytics           | EDA                    | DataFrame            | Analytics  |
| Models              | *Any classifier*       | Split Data           | Model      |
| Models              | *Any regressor*        | Split Data           | Model      |
| Evaluation          | Model Selector         | Model                | Model      |
| Evaluation          | Inference              | Model + X Test       | DataFrame  |
| Evaluation          | Evaluation             | Y Test + Predictions | Metrics    |