By: John Michael Pierobon
The File Transfer Protocol (FTP) is the standard means of transfering files across the Internet. Although many of its functions have been taken over by the HyperText Transfer Protocol (HTTP), FTP is still widely used to download and upload all kinds of files.
Files can be transfered between computers even if they are not compatible, as long as both computers support the File Transfer Protocol. A personal computer running Windows is incompatible with an Apple Macintosh because they are based on different computer architectures and run on different operating systems. Yet, with FTP, files can be transfered between those two incompatible computers. The same is true between a computer running UNIX and a personal computer running Windows.
FTP has many practical uses. Web content creators use FTP to upload their Web pages to a Web server. FTP is used to download evaluation software, and to obtain software patches. Corporations can store large files on a computer for later retrival instead of sending electronic mail with very large attachments, thus reducing network traffic.
There are two types of FTP: anonymous and authenticated. Anonymous FTP provides unrestricted access to files. Anonymous FTP is used to download free software, publications, press releases, etc. By convention, when anonymous FTP is used, one logs on to the remote computer with a username of anonymous or ftp, and as a courtesy, provides their electronic mail address as their password.
Authenticated FTP provides restricted access to files. With authenticated FTP the user must have an account on the remote computer, and provide a valid username and password. Authenticated FTP is commonly used to upload files, such as Web pages. At times authenticated FTP may be used to download files whose access is restricted to those have a valid username and password.
There are two principal modes of FTP transmission: ASCII and binary. Text files should be transfered in ASCII, so there is a proper conversion of end-of-line indicators. Binary mode is used for transfering programs, images, audio, compressed files, etc.
There are two types of FTP client interfaces: character-based
and graphical. The character-based interface of FTP uses a command line syntax
similar to that of DOS. It uses commands such as get to download
a file, and put to upload a file.
There are several inexpensive software packages that provide a graphical user interface for FTP. Fetch is an easy-to-use, full-featured FTP client for the Apple Macintosh. CuteFTP and WS_FTP are by far the two most popular file transfer software application packages for Windows. Igloo FTP, Queue FTP, and FTP Explorer are other inexpensive graphical interface software packages available for file transfer.
Links that download software rather than opening a new Web page use the file transfer protocol. Hence many Web surfers use FTP without knowing it or having a client interface software package.