A hyperlink is a reference to data (in this case your Wetu itinerary links) that the client can directly follow either by clicking on or by hovering over. If a hyperlink is clicked on your client will go directly to the information you want them to see without them having to copy and paste the URL.
Using a hyperlink is useful when the URL (i.e. [www.URL.com](http://www.URL.com)) is too long or unattractive.
Each email program will look a little different, however, we have tried to cover the basics. Most of the time the process is very similar.