LibGuides provides two kinds of link boxes, Links and Lists and Simple Web Links.
In a Simple Web Links box, you enter the name of the link, the URL, and an optional description of up to 256 characters. The links appear in a bulleted list, with the descriptions appearing when you move the cursor over the name.
In a Links and Lists box, you enter the the name of the link, the URL, an optional description of up to 256 characters, and (also optional) additional information of unlimited length. The links appear in a bulleted list with the descriptions beneath the names and, if there is additional information, an icon 
that you click on to bring up that information.
This page describes the advantages of link boxes and differences between the two types of link boxes.