FTP is a file transfer protocol thats used to get files from A to B. In a marketing sense a (secure) FTP-Server many times linkes two companies/services to transfer data.

Examples

1) When you want to put stuff on your website (e.g. WordPress) you’re very likely going to connect to your webspace with some FTP-Software.

2) Your graphic agency might want to give you access to big files continuously.

3) You want to connect your database (customer data) to an email-service provider.

How

A (S)FTP-Connection usually consists of four (five) parts:

1) Username
2) Password
3) Servername
4) Port
5) optional Key-File

Basically you just have to enter the right data in the right field. The most basic FTP-Connection is not very secure and will use the port 21. The Servername could look like a normal domain (e.g. website.com often times ftp.website.com) or also like an IP-Address (e.g. 127.0.0.1)

About 5) If possible, use SFTP (S = Secure). Sometimes you’ll need a SSH-Key-File for that case. This might be a bit more complicated and varies for each case so you’ll might have to do some searching / reading on your specific case.

Software

I use Cyberduck, if you want to look for something else just google it.