# Components and Dynamic Zones

> Source: https://docs.strapi.io/cms/api/entity-service/components-dynamic-zones

Use the Entity Service API to create and update components and dynamic zones while creating or updating entries. Components are single objects while dynamic zones are lists of components with a `__component` type identifier.

:::caution
The Entity Service API is deprecated in Strapi v5. Please consider using the [Document Service API](/cms/api/document-service) instead.
:::

The [Entity Service](/cms/api/entity-service) is the layer that handles [components](/cms/backend-customization/models#components-json) and [dynamic zones](/cms/backend-customization/models#dynamic-zones) logic. With the Entity Service API, components and dynamic zones can be [created](#creation) and [updated](#update) while creating or updating entries.

## Creation

A [component](/cms/backend-customization/models#components-json) can be created while creating an entry with the Entity Service API:

```js
strapi.entityService.create('api::article.article', {
  data: {
    myComponent: {
      foo: 'bar',
    },
  },
});
```

A [dynamic zone](/cms/backend-customization/models#dynamic-zones) (i.e. a list of components) can be created while creating an entry with the Entity Service API:

```js
strapi.entityService.create('api::article.article', {
  data: {
    myDynamicZone: [
      {
        __component: 'compo.type',
        foo: 'bar',
      },
      {
        __component: 'compo.type2',
        foo: 'bar',
      },
    ],
  },
});
```

## Update

A [component](/cms/backend-customization/models#components-json) can be updated while updating an entry with the Entity Service API. If a component `id` is specified, the component is updated, otherwise the old one is deleted and a new one is created:

```js
strapi.entityService.update('api::article.article', 1, {
  data: {
    myComponent: {
      id: 1, // will update component with id: 1 (if not specified, would have deleted it and created a new one)
      foo: 'bar',
    },
  },
});
```

A [dynamic zone](/cms/backend-customization/models#dynamic-zones) (i.e. a list of components) can be updated while updating an entry with the Entity Service API. If a component `id` is specified, the component is updated, otherwise the old one is deleted and a new one is created:

```js
strapi.entityService.update('api::article.article', 1, {
  data: {
    myDynamicZone: [
      {
        // will update
        id: 2,
        __component: 'compo.type',
        foo: 'bar',
      },
      {
        // will add a new & delete old ones
        __component: 'compo.type2',
        foo: 'bar2',
      },
    ],
  },
});
```