# AML Model

> The AML Model block maps a database table or SQL query to dimensions and measures, giving Holistics the structure it needs to explore and aggregate your data.

## Introduction

A Model in AML represents either a database table or a SQL query, and contains dimensions and measures that define how data can be explored and aggregated. Models are declared in `.model.aml` files (one model per file).

## Model types

AML supports two types of models:

- **[Table Model](/reference/aml/table-model)**: Built on top of a physical database table
- **[Query Model](/reference/aml/query-model)**: Built on top of a custom SQL query

## Common parameters

These parameters are shared by both Table Models and Query Models:

Parameter name      | Description
--------------      | ------------
type                | Model type: `'table'` for Table Model, `'query'` for Query Model
label               | User-friendly name for the model that appears in the Dataset exploration UI
description         | Description of the model. Support Markdown.
data_source_name    | The database on which Holistics will execute the SQL generated from this model
owner               | Define who should be in charge of managing the current model
dimension           | Define a dimension. See [Model Fields](/reference/aml/field)
measure             | Define a measure. See [Model Fields](/reference/aml/field)

## Basic syntax

```aml
Model model_name {
  type: 'table'  // or 'query'
  label: "Model Label"
  description: "Model description here"
  data_source_name: 'your_datasource_name'
  owner: 'user@your-domain.com'

  dimension dimension_name {
    label: 'Dimension Label'
    type: 'text'
    definition: @sql {{ #SOURCE.column_name }};;
  }

  measure measure_name {
    label: 'Measure Label'
    type: 'number'
    definition: @aql count(model_name.dimension_name) ;;
  }
}
```

## See also

- [Table Model](/reference/aml/table-model)
- [Query Model](/reference/aml/query-model)
- [Model Fields](/reference/aml/field)