A horizontal portal is a web portal that serves as a virtual gate to many similar or diverse web properties. In other words, if a portal houses links to a variety of external sites, it’s a horizontal portal. Most horizontal portals have multiple links to several different topic-specific vertical portals such as science blogs, online sports channels, news websites, mail features, calendar apps, etc.
Also called megaportals or horizontal enterprise portals, horizontal portals have an online search engine at their core and also offer users the option to customize the page. The portal’s focus is to present something for everyone, wanting to appeal to every kind of user.