FTP stands for File Transfer Protocol. These are used to transfer files computers over the Internet. Below is list of some good free FTP clients.

1. FileZilla : FileZilla is open source software distributed under the terms of the GNU General Public License.

2. Core FTP : This free, secure FTP client gives you a fast, easy, reliable way to update and maintain your website via FTP. It also provides a secure method (via SSL, TLS, or SFTP) to upload / download files to and from FTP servers.

3. WinSCP : Free SFTP, FTP and SCP client for Windows.