Doorway pages are defined as low-quality pages (or groups of pages, or entire websites) optimized to rank well for specific keywords that act as a door between users and content.
nofollow is a value that can be assigned to the rel attribute of an HTML a element to instruct some search engines that the hyperlink should not influence the ranking of the link's target in the search engine's index.v
A title tag is an HTML element that specifies the title of a web page. Title tags are displayed on search engine results pages (SERPs) as the clickable headline for a given result, and are important for usability, SEO, and social sharing.