How can we navigate using Lightning:navigation in Salesforce?

Lightning:navigation is used to navigate to a given pageReference or to generate a URL from a pageReference. To navigate, we need to define a PageReference object.
Pagereference is a javascript object that references a page, providing a well-defined structure that describes the page type and its corresponding values.
The following are supported features where we can navigate to:
Lightning Component
Knowledge Article
Named Page
Navigation Item Page
Object Page
Record Page
Record Relationship Page
Web Page