...as stated in the tutorial here:
3.2 Creating the Blog Application
To begin, open a terminal, navigate to a folder where you have rights to
create files, and type:
$ rails new blog
This will create a Rails application called Blog in a directory called
You can see all of the switches that the Rails application builder
accepts by running rails new -h.
After you create the blog application, switch to its folder to continue
work directly in that application:
$ cd blog <---*****DID YOU DO THAT???