An ftp server is a repository for downloadable files, which may be documents, software, music, device drivers, or anything else you can get into digital format. This allows people to call in at any time of day or night to download these items, with no attendance at the provider's end.

It is now very common for product manufacturers to post manuals and parts lists on an ftp site in PDF (Adobe Acrobat) format for ftp download. The customer can easily print out these items on their own laser printer. This greatly enhances the usability of the products at little expense. Credit applications and other forms and documents are also commonly posted on ftp sites, as well as software updates and other purely digital items.

It is also easy for customers to upload items to an ftp site. This requires an actual ftp client program as upload isn't built into Web browsers, but this software is easily available (and there are free versions you can post on your ftp site for downloading by your customers). Unix, Linux, OS/2 and some versions of Windows have ftp clients included, though these tend to be a bit basic.

To access an ftp server, the user needs a login name and password, but many ftp servers offer "anonymous ftp" access. Here the login name is "anonymous", and a password is not required (some anonymous ftp sites require an email address as password, but have no way to check if it is valid). Anonymous users can only access directories specifically made available for them.

How do you set up an ftp server? Well, if you are using a business grade Internet service account, your ISP can probably supply you with ftp service in addition to Web space and email. It may already be included and you just didn't know about it. If you are hosting your own Web server, an ftp server probably came with your server operating system. To make items available for download, you just copy them into the directories the ftp server allows client access to.