For SEO purposes, it's best to choose between www and no www. See how to do it with Nginx.
If you don't want to include www as your primary domain, it's nice to still allow traffic with and without the www in the domain name. For example, if your primary domain is example.com, you'd also want to allow traffic to www.example.com.
It is ideal for SEO (search engine optimization) purposes that you choose one (with or without www) and stick with it by redirecting traffic from the other domain to your main domain.
With Nginx as your web server, the proper way of doing so is to perform a
301 redirect in a separate
server directive. Use the following in addition to your main
return 301 $scheme://yourdomain.com$request_uri;
Note: It's okay to have multiple directives in one file, but it's good to keep the directives separate from one another.
In this case, we're getting rid of the www and considering yourdomain.com to be your main domain. You could just as easily do the reverse, like so:
return 301 $scheme://www.yourdomain.com$request_uri;
When you have a static site, sometimes you want to get rid of the HTML extensions and those pesky trailing slashes. Here's how I've done it.
Each filetype has its own place on the web. See where they fit in.