FTP is one of the earliest Internet protocol was developed, and is still used today to perform the download (download) and penggugahan (upload) files between your computer and FTP server FTP client. An FTP Client is an application that can issue commands FTP to an FTP server, while the FTP server is a Windows service or daemon that runs on a computer that responds to commands from an FTP client. FTP Commands can be used to change directories, change the transfer mode between binary and ASCII, evocative computer file to the FTP server and download files from FTP servers.
An FTP server is accessed by using the Universal Resource Identifier (URI) using ftp://namaserver format. FTP clients can contact the FTP server by opening the URI.
How the FTP protocol
FTP protocol uses Transmission Control Protocol (TCP) for data communication between client and server, so that in between these two components will be made a communication session before data transfer begins. Before making connections, TCP port number 21 on the server side will "listen" test connections from an FTP client and then will be used as a controller port (control port) to (1) create a connection between the client and server, (2) to allow clients to send an FTP command to the server and also (3) return the server response to the command. Once the control connection has been made, then the server will start to open the TCP port number 20 to form a new connection with a client to transfer the actual data being exchanged when performing a download and penggugahan.
FTP only uses standard authentication methods, namely using the username and password are sent in unencrypted form. Registered users can use his username and password to access, download, and upload the files he wanted. Generally, registered users have full access to several directories, so they can create files, create directories, and even delete the file. Users who are not registered can also use the anonymous login method, namely by using an anonymous username and password are filled in using e-mail address.