This name tells us that the molecule has three carbons and has a double bond in it.
pro means three carbons when talking about hydrocarbons
ene means the presence of at least 1 double bond
ane means all single bonds and yne means at least one triple bond which means that propane is a three carbon molecule with only single bonds connecting them while propyne has three carbons with a triple bond between 2 of the carbons.
I hope this helps. Let me know if anything is unclear.
