Doorway Pages (also known as bridge pages, portal pages, jump pages, gateway pages, ...) is a term used to refer to the website SEO or sub-pages are created for the purpose of intermediate bridge , redirect the user from the initial request page to page or other website content, with the aim to get a high ranking for a particular search query.
Doorway Pages are often considered SEO spam tricks (black hat) by them will redirect users directly to a new website, other than the original site they want to visit. And users will fall into a completely passive and may not know they have been moved to a different website. Moreover, Doorway pages can be harmful to the user because this technique can create a series of pages with an entrance on the SERP ranking and redirect the user to the same destination.