File Transfer Protocal (FTP) is a common way to transfer files between the local computer to a website and vice-versa. In order to move files from a computer to populate a website, those files need to be transferred in much the same way you would transfer files between two disk drives.

Firefox has a popular and easy to use (also free) FTP plug in called FireFTP downloadable from Mozilla.org. Such protocals are built into web editors like Dreamweaver.