Orange Pekoe is the classification of black tea post manufacturing of the leaf. It depends on the size of the leaf and the location of the leaf in the tea plant. The leaf curled is the pekoe. It is the richest in tannin, caffeine and is highly aromatic.
Often people think that as the name is orange pekoe, the tea will be infused with orange flavor and will have the aroma of an orange. That is a myth.