Doorway pages in SEO are defined as a page made specifically to rank well in search engines for particular keywords, serving as an entry point through which visitors pass to the main content.
The main goal of doorway pages is to be more easily found by search engines with specific keywords, which in turn would bring more traffic to the intended pages. These can be helpful for website owners in order to make a connection to the target page.
In practice, usage of doorway pages varies considerably and these pages themselves range from unique, content-rich pages to generic, keyword-stuffed pages.