What is File Transfer Protocol (FTP) and How Does it Work?

Fast, trustworthy, paperless.

Any two computers that are on the same network (and that can be on the Internet) can transfer files using the File Transfer Protocol. There’s an application in there, known as “ftp,” that directs the actual protocol (FTP) to transfer files. Here’s how it all goes down:

A person runs an FTP client application on one computer.

Another computer runs an FTP server program. That might be as an “ftpd” (FTP daemon) on a UNIX/Linux computer.

It could also be an FTP service on other platforms.

Here’s what File Transfer Protocol can do:

Transfer files between computers.

Create directories.

Remove directories.

List files.

You can count on FTP to deliver files cleanly. Attaching large files in an email can fail at times—as you’ve probably experienced—or it can freeze up a computer for long stretches of time.

Because FTP uses the TCP (networking) protocol, it operates though a reliable connection as a transfer “session” between the client (host) and server (remote) computers.

How it happens: To either send (download) or receive (upload) files using FTP, you use an FTP client (or client software) to connect to an FTP computer (server) that’s running FTP server software.

FTP is a three-in-one tool: It is a protocol, an application/program, and a helpful and valuable service. If you’re not an FTP site (the remote computer), then you’re a user on a local computer. When you “FTP,” as it’s called, you’re using the FTP client application to connect to the remote computer that provides the service. The actual FTP protocol gets used anytime you transfer files using the application.

On my command: At one time, file transfers were text-based and the remote user had to interact with the server onscreen by entering requests or “commands” line by line. The user had to enter in Start and Stop commands and navigate through a directory to make the file transfer happen.

But today, most FTP programs are user-friendly and graphically oriented, offering an easy-to-use interface for moving files between computers. Today, FTP clients/servers (remote computers) display the file resources onscreen in a way that makes it easy to identify the exact file you want to send, and exactly to whom.

In addition to allowing you to send large files that would crash as an email attachment, FTP typically lets you see, with certainty, that a file is on the server, and it lets you know if and when the transferred file reached its destination.

Downloading free content with FTP.

The Internet offers us a number of public FTP servers that are known as anonymous FTP sites or anonymous FTP archives. They offer you content/information/files that you can download for free…movies, music, graphics. If you were to use an anonymous site, you would use the name anonymous as your username and your email address as your password.

Businesses, colleges and other universities upload a variety of files you can explore and download, if they interest you. Just be sure to use a firewall and a good antivirus program to ensure you’re not downloading anything that could infect your computer with a virus.

Most of the time, you don’t have to worry whether your operating system (Windows, Apple OX, Linux) is the same as that of an FTP server. To computers, the TCP/IP protocol is the only thing that matters. Sometimes, however, you might have to download FTP server software to make it work.

Finally, FTP transfers aren’t necessarily secure. Be sure to explore the security features of FTP services before jumping right in.