Using the HTML5 <nav> tag is important when the author has to determine a specific section of the navigation links. The main role of the HTML5 <nav> tag is to establish major block for the navigation links.
It has to be noted though that not all links that are included in the HTML document has to be placed inside the HTML5 <nav> tag.
The HTML5 <nav> tag is a new element that is not present in HTML4.01.
Using the HTML5 <nav> tag has no complications because all the major websites can interpret this well. Aside from that, the HTML5 <nav> tag is also compatible with the Event Attributes and Global Attributes in HTML5.