# Component Facets

A facet is any attribute of type `Aura.Component[]`. Use this type as a placeholder for a block of markup. The `body` attribute is an example of a facet.

To define your own facet, add an `aura:attribute` tag of type `Aura.Component[]`, which is an array of components, to your component. For example, let's create a component called `facetHeader.cmp`.

```nolang
<!--c:facetHeader-->
<aura:component>
    <aura:attribute name="header" type="Aura.Component[]"/>

    <div>
        <span class="headerClass">{!v.header}</span><br/>
        <span class="bodyClass">{!v.body}</span>
    </div>
</aura:component>


```

This component has a `header` facet. Note how we position the output of the header using the `v.header` expression.

The component doesn't have any output when you access it directly as the `header` and `body` attributes aren't set. Let’s create another component, `helloFacets.cmp`, that sets these attributes.

```nolang
<!--c:helloFacets-->
<aura:component>
    See how we set the header facet.<br/>

    <c:facetHeader>

        This is the component body for facetHeader.

        <aura:set attribute="header">
            Hello Header!
        </aura:set>
    </c:facetHeader>

</aura:component>


```

The `aura:set` tag sets the value of the `header` attribute of `facetHeader.cmp`.

The `body` attribute is special. You don’t need to use `aura:set` if you’re setting the `body` attribute. Any free markup that’s not enclosed in one of the tags allowed in a component is assumed to be part of the body and is set in the `body` attribute.

If you use `c:helloFacets` in an app, the output is:

```nolang
See how we set the header facet.
Hello Header!
This is the component body for facetHeader.
```

**See Also**

- [Component Body](/docs/platform/aura-platform/guide/components-body.md)
- [Framework-Specific Types](/docs/platform/aura-platform/guide/ref-attr-types-aura.md)