Alkanes :Alkanes are the hydrocarbons containing only single bond between all the carbon atom are called alkanes. They are also known as saturated hydro carbons
Alkenes: Alkenes are the hydrocarbons containing at least one double bond between two carbon atom are called alkenes. They are known as unsaturated hydrocarbons
Alkyne: Alkynes are the hydrocarbons containing at least one triple bond between carbon atoms are called alkynes. They are known unsaturated hydrocarbons
so from above mentioned definitions and characteristics, difference between alkane, alkene and alkyne is clear.