How to hide the url path in html

When I upload my website files to my server and goto my website, i see the index.html at the url bar of the browser. How can I hide this?

//bakpinar.com/about/about-us.html

I would like it to look like in this example;

//www.royaltyline.com

as you can see, you only see the website address in the url bar of the browser. And when you click to another page, it doesnt show the .php, .asp or .html extension, just shows the folder name.

LINK NAME , but will appear on your website as "LINK NAME" with the URL hidden.