To present a more professional appearance, you can easily eliminate .html from your website.
Create an .htaccess file and enter the following code:
RewriteEngine onRewriteCond %{THE_REQUEST} /([^.]+)\.html [NC]
RewriteRule ^ /%1 [NC,L,R]
RewriteCond %{REQUEST_FILENAME}.html -f
RewriteRule ^ %{REQUEST_URI}.html [NC,L]
This .htaccess code will remove .html from all of your file names.