How does pneumonia differ from ptb?

Pulmonary Tbc: Pulmonary tuberculosis (if that is what you meant by this abbreviation) is one potential cause of "pneumonia". Pneumonia, or pneumonitis is inflammation of the tissues of the lung, usually confined to the air spaces and the intraalveolar septi (alveolae and the walls between them), excluding the airways themselves (bronchi, bronchioles, etc.). Hope this helps. If not, repeat the question.