If you have set up your own server, someone has done it for you or are paying for hosting you will probably want to use FTP to get the Web pages to the server.  You do not need FTP for XAMPP.  To use FTP you will need:

Start the FTP client and you should see something like this:Filezilla before loggin on

Locations

Type the FTP server's log in details and press the Quickconnect button.  On the left in the lower part of the window are the files on your local computer (the one you are using).  On the right are the files on the server.  If the server has been set up properly then the right should show either an empty folder or a folder with some Web pages in.  If you see a folder/directory called htdocs or public instead of HTML files you probably need to double click on the folder to go into it.  That is where the pages will need to go.

Filezilla saves your log on details so next time just use the drop down (next to the Quickconnect button).

Uploading

To upload a file you need to find it on the left, make sure the correct destination is open on the right and double click on the file on the left.  You can also select multiple files and right click on them to upload or drag them to the right.  If the files exist on the right it will ask you to confirm before they are replaced.

You can download the files from the right to the left as well so be careful not to do that by accident.

Security

The original version of FTP is not secure.  If you are using paid hosting make sure they offer sFTP which encrypts the data before it travels across the Internet.