I don't exactly know how to describe this so I'll just use an example.

In some sites lately when you click a link you get redirected and its been shown as a folder.

What I mean is, lets say for example that you are clicking at support.html

What I mean is that it will now be shown as wwwm,site,com/support/ and not support.html

I thought the simple way of making folders with the name shown and just putting an index.html inside but someone told me that this is done with .htaccess file. I am not sure if he knew what he was saying...so I need your help now

With Apache's .httaccess, you can easily add a RewriteRule that will redirect a certain url prefix/regex to some url. With rewrites, one can even set it to do reverse proxy mode where the url stays on /support/ but is actually reading the contents of /some/other/dir/support.html or something).

Read more on Apache's RewriteRule for more information.

I see....so that whole thing has to do with the .htaccess file only.

And this "feature" that I will use is at any way slowing down the browsing?

No, a Rewrite should be fast (almost negligible processing time). Not unless you have thousands of rewrites on your .htaccess

Ok thanks for the info mate.

no problem =)