In Drupal 8 form API is similar to Drupal 7 Form API. forms still uses array structure to render the data. but having separate validation and submission form.Drupal 8 has some new (HTML 5) elements available.
New HTML 5 elements like
Whether you are familiar with Composer or not, using it to manage dependencies on a Drupal project entails its own unique set of best practices. In this article, we will start by getting a Composer-managed Drupal project set up