FTP

Stands for File Transfer Protocol. FTP allows you to copy or send files (HTML-documents, graphic images, spreadsheets) from one computer to another via the Internet. 

FTP - An application layer protocol that uses Transmission Control Protocol (TCP) and telnet services to transfer bulk-data files between machines or hosts. A method of moving files between two Internet sites.

A protocol which allows a user on one host to access, and transfer files to and from, another host over a network. Also, FTP is usually the name of the program the user invokes to execute the protocol. FTP is a special way to log in to another Internet site for the purposes of retrieving and/or sending files.

You need to have the computer address, username and password to login into some computer (both of you must be connected to internet)

Host Address: Usually IP address or a domain name.
Username: The username assigned to you to login into particular computer
Password: The password assigned to you to login into particular computer

Put the above mentioned details into an FTP client software which would connect you to that particular host/computer and then you can browse the host just like your own hard drive depending upon what host/computer allows you to see, download and upload.

FREE FTP software:

• FTP Commander 
  A basic, easy-to-use freeware FTP client. Offers all the functions of the Web's most popular FTP client, WS_FTP, except that this is unconditionally free. You can delete, rename and copy files, as well as create and delete directories on the FTP server. FTP Commander is freeware; unlike the second FTP client listed here, FTP Navigator, (which is shareware).
  
  
  
• BitTorrent 
  A free, open-source peer-to-peer program, BitTorrent has become a big hit with people looking to rapidly download massive multimedia files (such as movies). What makes BitTorrent unique is that, the more popular a file is, the faster it downloads to your computer (as the program uses every downloader's upstream bandwidth). (For Windows, Mac, and Linux).
  
  
  
• Net Vampire 
  (Note: this program is no longer freeware, but a free 30-day trial is available). If you surf around a lot and spot files here and there that you'd like to download, then you need this useful program. Just drop-and-drop the URLs to Net Vampire and you can do all your downloading in one batch. Net Vampire resumes broken connections and restarts downloads. It's also specially designed to deal successfully with noisy servers and unreliable links. It also offers features such as a built-in search engine, true site testing and support for many proxy types. New version adds more features, including an on-the-fly ZIP viewer and a multi-lingual user interface, which supports 14 languages.
  
  
  
• NetAnts 
  Fed up with waiting forever to download files? Here's a helpful free download manager that is designed to maximize your throughput by making multiple FTP or HTTP connections, (each of which downloads a separate part of a single big file). NetAnts offers lots of features and is available in many languages. (For Windows).
  
  
  
• SmartFTP 
  A solid freeware FTP client, SmartFTP offers loads of handy features, including a Windows Explorer-like interface, drag & drop support and resumption of broken transfers. (For Windows). Free for personal, as well as educational and non-profit usage.
  
  
  
• AceFTP 
  One of the Web's most popular freeware FTP clients, this easy-to-use program offers advanced features and gives you the ability to open several FTP sites at once and execute multiple file transfers concurrently. AceFTP resumes broken transfers and lets you preview files with its integrated viewer. (For Windows).
  
  
  
• FTP Explorer 
  (Note: this program is no longer free). Here's a powerful, fully featured FTP client that offers a Windows Explorer-like interface and is easy to use. (For Windows).