Redirect www to non-www nginx configuration

Redirect single domain with www to non-www. For example, redirecting of to

Why do we need to redirect www to non-www or vice versa?
It all because of SEO purposes. Google treats your content as duplicate when they are crawl-able from both www and non-www.

Nginx configuration for single domain redirection of www to non-www .

server {
        return 301 $scheme://$request_uri;

Nginx configuration for multiple domains redirection of www to non-www.

server {
        server_name "~^www\.(.*)$" ;
        return 301 $scheme://$1$request_uri;