# Limitations

Limitations are part of the permissions system. They limit the access granted to users by [policies](https://doc.ibexa.co/en/latest/permissions/permission_overview/index.md). While a policy grants the user access to a function, Limitations narrow it down by different criteria.

Limitations consist of two parts:

- `Limitation` (Value)
- `LimitationType`

Certain limitations also serve as role limitations, which means they can be used to limit the rights of a role assignment. Currently, this covers [subtree of location](https://doc.ibexa.co/en/latest/permissions/limitation_reference/#subtree-limitation), [Section](https://doc.ibexa.co/en/latest/permissions/limitation_reference/#section-limitation) and [Personalization access](https://doc.ibexa.co/en/latest/permissions/limitation_reference/#personalization-access-limitation) limitations.

`Limitation` represents the value, while `LimitationType` deals with the business logic surrounding how it actually works and is enforced. `LimitationTypes` have two modes of operation in regard to permission logic (see [`Ibexa\Contracts\Core\Limitation`](https://doc.ibexa.co/en/latest/api/php_api/php_api_reference/classes/Ibexa-Contracts-Core-Limitation-Type.html) interface for more info):

| Method         | Use                                                                                                                                                                                                 |
| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `evaluate`     | Evaluates if the User has access to a given object in a certain context (for instance the context can be locations when the object is `Content`), under the condition of the `Limitation` value(s). |
| `getCriterion` | Generates a `Criterion` based on `Limitation` value and current user which `SearchService` by default applies to Search Criteria for filtering search based on permissions.                         |

## Limitation reference

See [Limitation reference](https://doc.ibexa.co/en/latest/permissions/limitation_reference/index.md) for detailed information about individual limitations.