# Source: https://nextjs.org/docs/pages/building-your-application/rendering/server-side-rendering.md

# Server-side Rendering (SSR)


> Also referred to as "SSR" or "Dynamic Rendering".

If a page uses **Server-side Rendering**, the page HTML is generated on **each request**.

To use Server-side Rendering for a page, you need to `export` an `async` function called `getServerSideProps`. This function will be called by the server on every request.

For example, suppose that your page needs to pre-render frequently updated data (fetched from an external API). You can write `getServerSideProps` which fetches this data and passes it to `Page` like below:

```jsx
export default function Page({ data }) {
  // Render data...
}

// This gets called on every request
export async function getServerSideProps() {
  // Fetch data from external API
  const res = await fetch(`https://.../data`)
  const data = await res.json()

  // Pass data to the page via props
  return { props: { data } }
}
```

As you can see, `getServerSideProps` is similar to `getStaticProps`, but the difference is that `getServerSideProps` is run on every request instead of on build time.

To learn more about how `getServerSideProps` works, check out our [Data Fetching documentation](/docs/pages/building-your-application/data-fetching/get-server-side-props.md).