HowtoInstallOnTextDrive : run command?


I try to install my local little site on my textdrive account.

So I read this :

But I’m very newbie, and I don’t understand the line :

1. run the command rails sites_directory/app_name

How “run” the command ? From what app ? From where ?

Can someone could tell me what are the software I need to install a
personnal site ?