# Views
> Nuxt provides several component layers to implement the user interface of your application.
## `app.vue`
By default, Nuxt will treat this file as the **entrypoint** and render its content for every route of the application.
```vue [app/app.vue]
Welcome to the homepage
```
If you are familiar with Vue, you might wonder where `main.js` is (the file that normally creates a Vue app). Nuxt does this behind the scene.
## Components
Most components are reusable pieces of the user interface, like buttons and menus. In Nuxt, you can create these components in the [`app/components/`](/docs/4.x/directory-structure/app/components) directory, and they will be automatically available across your application without having to explicitly import them.
```vue [app/app.vue]
Welcome to the homepage
This is an auto-imported component.
```
```vue [app/components/AppAlert.vue]
```
## Pages
Pages represent views for each specific route pattern. Every file in the [`app/pages/`](/docs/4.x/directory-structure/app/pages) directory represents a different route displaying its content.
To use pages, create an `app/pages/index.vue` file and add `` component to the [`app/app.vue`](/docs/4.x/directory-structure/app/app) (or remove `app/app.vue` for default entry). You can now create more pages and their corresponding routes by adding new files in the [`app/pages/`](/docs/4.x/directory-structure/app/pages) directory.
```vue [app/pages/index.vue]
Welcome to the homepage
This is an auto-imported component
```
```vue [app/pages/about.vue]
This page will be displayed at the /about route.
```
## Layouts
Layouts are wrappers around pages that contain a common User Interface for several pages, such as header and footer displays. Layouts are Vue files using `` components to display the **page** content. The `app/layouts/default.vue` file will be used by default. Custom layouts can be set as part of your page metadata.
If you only have a single layout in your application, we recommend using [`app/app.vue`](/docs/4.x/directory-structure/app/app) with [``](/docs/4.x/api/components/nuxt-page) instead.
```vue [app/app.vue]
```
```vue [app/layouts/default.vue]
```
```vue [app/pages/index.vue]
Welcome to the homepage
This is an auto-imported component
```
```vue [app/pages/about.vue]
This page will be displayed at the /about route.
```
If you want to create more layouts and learn how to use them in your pages, find more information in the [Layouts section](/docs/4.x/directory-structure/app/layouts).
## Advanced: Extending the HTML Template
If you only need to modify the ``, you can refer to the [SEO and meta section](/docs/4.x/getting-started/seo-meta).
You can have full control over the HTML template by adding a Nitro plugin that registers a hook.
The callback function of the `render:html` hook allows you to mutate the HTML before it is sent to the client.
```ts [server/plugins/extend-html.ts]
export default defineNitroPlugin((nitroApp) => {
nitroApp.hooks.hook('render:html', (html, { event }) => {
// This will be an object representation of the html template.
console.log(html)
html.head.push(``)
})
// You can also intercept the response here.
nitroApp.hooks.hook('render:response', (response, { event }) => { console.log(response) })
})
```