Layouts directory
Layouts are a great help when you want to change the look and feel of your Nux app. Whether you want to include a sidebar or have distinct layouts for mobile and desktop.
Default Layout
You can extend the main layout by adding a layouts/default.vue file. It will be used for all pages that don't have a layout specified. Make sure to add the <Nuxt> component when creating a layout to actually include the page component.
All you need in your layout is three lines of code which will render the page component.
<template>
  <Nuxt />
</template>
You can add more components here such as Navigation, Header, Footer etc.
<template>
  <div>
    <TheHeader />
    <Nuxt />
    <TheFooter />
  </div>
</template>
Custom Layout
Every file (top-level) in the layouts directory will create a custom layout accessible with the layout property in the page components.
Let's say we want to create a blog layout and save it to layouts/blog.vue:
<template>
  <div>
    <div>My blog navigation bar here</div>
    <Nuxt />
  </div>
</template>
Then you have to tell the pages to use your custom layout
<script>
export default {
  layout: 'blog',
  // OR
  layout (context) {
    return 'blog'
  }
}
</script>
Error Page
The error page is a page component which is always displayed when an error occurs (that is not thrown on the server-side).
layouts folder, it should be treated as a page.As mentioned above, this layout is special and you should not include <Nuxt> inside its template. You must see this layout as a component displayed when an error occurs (404, 500, etc.). Similar to other page components, you can set a custom layout for the error page as well in the usual way.
You can customize the error page by adding a layouts/error.vue file:
<template>
  <div class="container">
    <h1 v-if="error.statusCode === 404">Page not found</h1>
    <h1 v-else>An error occurred</h1>
    <NuxtLink to="/">Home page</NuxtLink>
  </div>
</template>
<script>
export default {
  props: ['error'],
  layout: 'blog' // you can set a custom layout for the error page
}
</script>