Obj-C Methods: Q re blog post!

Hi all. Have a newbie question after reading this article here on Treehouse: http://blog.teamtreehouse.com/the-beginners-guide-to-objective-c-methods

Ben gives examples of how to use methods. In this example he gives us:

1. NSString *emailAddress = @"ben@objectivecfun.com"
2. int stringLength = [name length];
3. // stringLength will equal 21!

And about this he says:

'The example above shows how a method is used. Here we are calling the length message on the name variable, or more accurately, sending the length message to the name object'

What I am failing to understand here is the reference to 'name' in the method call. Nowhere has name been defined, so how can he refer to a 'name' object that doesn't exist?

I am absolutely flummoxed by this. I realise there is some basic reason behind this that I don't get and I would be really grateful for help.