This method is applicable only if a File Manager (or similar) utility has been provided by your hosting company. The utility is generally located under the Control Panel of your account and so you need to login first. For instance, at my hosting accounts, the File Manager is displayed as an icon along with other utilities in the control panel. The File Manager icon looks like one below.
To use the File Manager, click on its icon. A new window opens and displays the directories at your web hosting account. [Refer image below]
You need to upload all website files to the document root directory which is www or public_html in the image above. Thus, all your website files need to reside in the document root directory.
If you click on the directory name, you get a set of links displayed on the top-right that let you delete, rename, change permission etc. for this directory. [Refer image below]
IMPORTANT: To transfer files to a particular directory, you need to first migrate to it.
To upload files, click on the Upload Files link (refer the above image). This should open a form through which you can select files from your system and upload them on your web hosting server. (Refer image below)
Using FTP to upload website files on your web hosting server
What you need is a special service to maintain files on your web site. The File Transfer Protocol (FTP) is just that. FTP is an Internet Protocol quite like HTTP (HyperText Transfer Protocol) which you would be familiar with. Using FTP you can quickly and easily manage the files on your web hosting server and the best way to do that is through FTP programs also known as FTP clients.