getStaticProps and getServerSideProps are two methods that allow you to fetch data and pre-render pages. The main difference between them lies in how and when the data fetching and page rendering occur.

1. getStaticProps:

   • This function is used for pre-rendering static pages at build time.

   • It runs during the build process and not at request time.

   • The data fetched in getStaticProps is used to pre-render the page as HTML.

   • The generated HTML is then reused for each request.

   • This method is suitable for pages that do not require frequent data updates.

   • When the data changes, you need to rebuild the entire application to reflect the updates.

2. getServerSideProps:

   • This function is used for server-side rendering (SSR) at request time.

   • It runs on every request made to the page.

   • The data fetched in getServerSideProps is used to dynamically generate the page's HTML.

   • This method is suitable for pages that require frequently updated data or require access to session-specific data.

   • As the data fetching happens on each request, changes to the data are immediately reflected when the page is requested.

To summarize, getStaticProps is used for pre-rendering pages at build time with static data that doesn't change frequently, while getServerSideProps is used for server-side rendering with dynamic data that may change on each request. The choice between them depends on the specific requirements of your application and the data you need to fetch.