It's a metaframe setup which allows users to terminal services(the ability to remote to a system to use a published application example, instead of installing Microsoft Word on their system they can remote to a server with citrix and use Microsoft Word or whatever application you want them to use)
Now, Citrix is a good way to secure the applications and have them work on a client's system using a seamless window meaning it's not going to run like terminal services where you have a window within a window, the seamless feature runs the application as if it's right on their machine. And it's running on TCP/IP, with security in mind you can encrypt sessions and compress the transfer rate since the only thing they're seeing is the graphic template of the application, any live data that they enter in can be stored on your citrix server or a connecting Database server. Now the downside of citrix, is the cost of licenses. It's more costly than a CAL license from Microsoft. In my setup over here I have a total of 10 remote sites which I have the citrix client installed on specific machines and I have 20 citrix licenses. but I also use Terminal Services locally with 65 CAL(Client Access Licenses) which means I have a good balance if licenses if not more to expand with. Sometimes you want to plan on your licenses before you go live a with a citrix server.
