The importance of links and linking.
A link or hyperlink is a clickable object on a webpage that leads from one page to another. Links may visibly appear as text, images, or buttons. We can classify links based on the destination of the link, whether it leads users to another page on the same site or a different website.
Internal links are links between the pages within your own website. Search engines determine this by looking at the domain name; if the links on a page link to other pages within the same domain, they are considered internal links.
Outbound links are those links on your website that link out to websites with a different domain name. In fact, an external or hyperlink is any link that was posted on another website but points to your web resource. Same way, when you insert a link to another resource on your site – it is called an external or outbound link.