factory girl build vs create

gistfile1.rb

#http://archived.rpheath.com/posts/411-how-to-use-factory-girl-with-rspec
describe Whatever do
  before(:each) do
    @user = Factory.build(:user)  # returns an unsaved object
    @user = Factory.create(:user) # returns a saved object
    @user = Factory(:user)        # shortcut for Factory.create()
  end
  
  it "should be a dumb test to show usage" do
    @user.name.should == "Ryan Heath"
    @user.email.should == "[email protected]"
  end
end

This StackOverflow Q/A does a great job of answering this question as well