Some passies are grown fruit for eating (is that what you are asking?) There are a few main edible types of passiflora flava carpa (yellow fruited) , purple fruited ( like fredrick or purple possum).
To further confuse us is the fact that the yellow fruited types need a pollinator from a different clone than themselves, whereas many of the purple fruited types are self fertile.
Other types are also edible but not as tasty (but taste is relative so...) mollissima,caerulea,p_ actina, lingularis, and some others. The taste also seems to depend on the enviornmental conditions/where the fruit is grown.

Most passies will make a 'fruit'. Some are empty and some have seeds for planting and are inedible. Many can be toxic if they are not ripe so be sure to eat only the edible types and only when they are sufficiently ripened.

Here is a good link and great site to explore,it is worth reading.
Hope I didnt confuse you more ;P ~SJN

Here is a link that might be useful: passionfruit