Anatomy
An inline link, within a paragraph, is simply displayed as an underlined text. When a link is used in a standalone way it used a heavier font weight and could optionally be combined with an icon to give it more weight and clarity.
Types
As mentioned, a link could either be used inline or in a standalone way. A link could also be internal (the user stays within the same website or application) or external (the link goes to another website or application). In case the link is external, there should be indication in the form of an icon.