Salam Anak IT. FileZilla FTP Client is one of the most popular FTP client available on the internet. It is used to upload and download files to/from server (usually web server). Click here to read further on FTP.
You may download FileZilla FTP Client for free on their website http://filezilla-project.org/ or simply clickhere if you would like to have a test drive. Once installed and opened, the following window will appear:
Then you may go to File>Site Manager or simply press CTRL+S keys on your keyboard.
To connect to the FTP Server using your account (if you have one), enter the given hostname (e.g websiteku.info) or it can be the Server's IP Address (if you know it). The default port for FTP is 21. Choose "Normal" for Logontype, enter your username and password then click on Connect button. If you have entered valid FTP account information, you will be connected to the server and ready to transfer files from your computer (client) to the server or vice versa.
Hope it gives you basic understanding on FTP (File Transfer Protocol). You may contact me if thing goes wrong with your FTP-ing attemp. Sekian.