Overview

FTP (File Transfer Protocol) is the standard method of transferring files from one computer to another across the Internet. This document attempts to provide a basic introduction to FTP, what it can do, and how you can use it. It is not designed to be an exhaustive guide to the intricacies of FTP, as most people will only ever use a few of its features.

What is FTP?

FTP (File Transfer Protocol) is a protocol (method of communication) designed to allow computers to communicate with each other across the Internet and arrange for the transfer of files from one computer's storage to the other's. Whilst FTP is a noun properly, it is often used as a verb, as in "I'll FTP those files across", meaning "I'll transfer those files from/to the target computer to/from my computer."

Can I get files from any computer on the Internet?

Not all computers on the Internet allow for or are capable of FTP. Firstly, the computer must run something called an FTP Server. This server manages connections from people wishing to retrieve or deposit files. In effect, an FTP Server is like a "window" on the remote computer's hard drive. The person who sets up an FTP Server controls what areas of the hard drive are visible, what files can be read or written, and who can access them. If no FTP Server has been set up on computer, that computer's files cannot be read using FTP.

Secondly, many FTP Servers are set up for private means, and access from anybody who is not authorised is controlled by a username and password method. This means that you must have been given explicit access to the Server, and assigned a unique name and secret password that must be provided to the server before being allowed to use its facilities.

Where can I use FTP?

As well as using FTP to administer your Web site, there are also many public-access archives of documents and software, shareware and public-domain. These are accessed by what is known as anonymous FTP, where the FTP Server requires a username, but that username is simply anonymous.

Is anonymous FTP really anonymous?

Anonymous FTP is a misnomer as, these days, when you use anonymous FTP, most FTP Servers will also require you to supply your e-mail address as a password. This means that the archive maintainers will have a record of your e-mail address cross-referenced with which files you transferred. However, most archive maintainers undertake that your e-mail address will be used only for their own purposes, those being demographic studies and in connection with pursuing those who abuse the archive services. You are extremely unlikely to receive unsolicited e-mail in connection with use of an anonymous FTP archive.

How can I use FTP?

There are a large number of programs available that can be used for FTP, with varying user interfaces. The most basic is a program called, perhaps confusingly, ftp. This offers a command line interface, similar in some ways to DOS or UNIX shell, which can be used to explore the directory tree of a remote computer and transfer files. It has one main advantage, in that it is standard and has been written for most computer platforms.

There are also numerous programs available which give you a more graphical, point-and-click interface to FTP. Space does not permit a discussion of the various programs available for the different platforms, but you may care to look at, for instance, Shareware.com or the Tucows archive for examples. It is also worth noting that most Web browsers can also be used to fetch files via the FTP protocol, but a discussion of how this is acheived is beyond the scope of this document.