One of the primary reasons for the Internet was to be able to easily reference research when citing others, with an ability to directly “link” to their work.
In computing, a hyperlink, or simply a link, is a reference to data that the reader can directly follow either by clicking, tapping, or hovering. A hyperlink points to a whole document or to a specific element within a document.
Hypertext is text with hyperlinks. The text that is linked is called anchor text. A software system that is used for viewing and creating hypertext is a hypertext system, and to create a hyperlink is to hyperlink (or simply to link). A user following hyperlinks is said to navigate or browse the hypertext. 
Note Link text should be specific about where the user will be going if they click a link. This means that links should not be simple text such as “Click Me!” Instead, good style would dictate that the link text be a description of the site, name, or information that informs the user.
With links being such a basic and historical part of the Internet, they also have a very simple tag;
<a>...</a>. Any text between a hyperlink element’s tags will display as “hypertext”. Traditionally, this has been blue, underlined text, visually signifying to the user that the text is a link.
In order to link to another document, the author must include a hyper-reference attribute within the opening tag. This attribute is signified with
# is a URL placeholder.
<a href="#">link text</a>