[Help-smalltalk] Objects and classes

[Mark Carter]

I'm REALLY new to Smalltalk. In a previous thread, I created a file  
Hello.st:

Object subclass: #Hello
       instanceVariableNames: ''
       classVariableNames: ''
       poolDictionaries: ''
       category: ''!


"Create a method"
!Hello methodsFor: 'speaking'!
publish
    Transcript show: 'Greetings. '!

! !

To load it, I do
FileStream fileIn: 'Hello.st' !

BUT, if I want to "run" Hello, I have to do
Hello new publish

My question is: why did I have to `new` Hello, whereas I don't have to  
`new` FileStream? Presumably for Hello I have to create an object by  
instantiating a class, whereas with a class like FileStream I don't  
have to. What's going on? Are there methods which only belong to  
classes and not objects, and if so, how do I define them?

Sorry if the question seems really dumb.