Query in ca final select case laws

In the select case studies of CA final for May 2012, pertaining to Direct tax, in case no.2 Joseph George & Co. v/s ITO (2010) It has been decided that the business of letting out of property is taxable as income from house property as against Lodging, which is taxable as Profits and Gains of business and profession.

My query is that what is the criterion of distinguishing the Lodging and Letting out?

Thanks in advance!