When creating application using CodeIgniter by default the URL will be as follow:
http://www.mydomain.com/index.php/home
When you want to shown as
http://www.mydomain.com/home
Solution
Put a file .htaccess in your root application folder
The file .htaccess content is
RewriteEngine on
RewriteCond $1 !^(index\.php|images|css|js|robots\.txt)
RewriteRule ^(.*)$ /your-root-folder/index.php/$1 [L]