Deep Linking
Deep links are a type of hyperlink that direct the viewer to specific content, images, or videos on another website. Links to a home page or a main page are not deep links.
Deep links can cite the precise paragraph or page within a website where specific content is found, making it easier for the website user to obtain the precise information or content he or she is searching for. Say you're looking for medical information on the flu. It's a lot easier to click on a Deep link that takes you straight to the Mayo Clinic's "Viral Flu" page rather than clicking on a link that takes you to the Mayo's homepage, from which you then have to navigate your way to find the specific information you need.
Deep linking is an effective SEO technique that can increase website traffic, if done properly, by pushing the website's ranking up on search engines. It's a way of saying to search engines that this website has real information and it's carefully put together.