After installing Joomla, by default you will see /index.php/ in the URLs. This is easy to change in 2 steps.

Why do you want to remove index.php from the URL?

Search engine friendly (SEF) URLs are human-readable or clean URLs that make sense to both humans and search engines because they explain the path to the specific page they point to.

The index.php says nothing but is technically necessary without this modification.

Before:

After:

Use URL rewriting

Go to "System > General settings" and set Use URL rewrite to "Yes"

Modify htaccess.txt file name

If you are using an Apache server, make sure mod_rewrite is installed and enabled on your hosting account. Go to your website with an FTP programme and locate the htaccess.txt file in the root folder of your site. Rename the file to .htaccess (dot htaccess).

Now the .index.php will be removed from your URLs.

URL rewriting on an IIS 7 Server

If you're using an IIS 7 server, make sure the IIS URL Rewrite Module is enabled for your hosting account. Rename the file "web.config.txt" to "web.config" (i.e. without .txt) before activating the URL rewrite option.