As what the name suggests, the new "nav" element is for Navigation. Yes, "nav" element is meant for the area with collection of site navigational links.
Navigational links of a website are mostly placed at the header and sidebar, sometimes, it can be in footer.
However, Not all groups of links on a page need to be in a nav element - only sections that consist of major navigation blocks are appropriate for the nav element. In particular, it is common for footers to have a short list of links to various pages of a site, such as the terms of service, the home page, and a copyright page. The footer element alone is sufficient for such cases, without a nav element.
Below is an example of how can we use nav element, it is usually nested with ul element (unordered list) for navigational links.