Alkenes and alkynes are unsaturated. This means???

um.. I honesly don't know what this means!

http://en.wikipedia.org/wiki/Unsaturated_compound

Since this is not my area of expertise, I searched Google under "unsaturated alkenes to get this source:

http://en.wikipedia.org/wiki/Alkene

Click the hypertext for "unsaturated."

I hope this helps. Thanks for asking.

I didn't read either of the references cited by others who responded but alkenes contain double bonds between carbon atoms and alkynes contain triple bonds between carbon atoms. Alkanes, on the other hand, are saturated and they contain single bonds to each carbon atom.