FTP is a protocol for transferring data between computers in computer networks. It does not depend on the operating system and so works on Windows, Linux, Unix and others.
Modern web browsers already include an FTP client that can work with data over this protocol. An FTP client is usually designed so that you can manipulate the data the same way as on your own computer. In a browser, FTP access is done by adding ftp:// before the domain name. FTP access can be secured with a username and password.
Use
This protocol is most often used for sharing data (video, music). Another use is, for example, access to a website's files on web hosting.