Alkynes
An alkyne is a hydrocarbon that contains a triple bond. One or more carbon atoms are joined by the triple bond. The triple bond results in alkynes being more reactive but having lower stability. The most simplest alkyne is ethyne (acetylene). Alkynes have a specfic property which makes them useful in everyday life - they burn readily in air.
References
OXFORD. Chemistry for the Biosciences - The essential Concepts. Tony Bradshaw, Jonathan Crowe and Paul Monk (2006).