Which is better to build a deck? From real wood or a composite material?

Composite decking will last much longer than wood, never need staining, no worry about splinters and is just as easy to work with as wood decking. The cost of composites is much higher than pressure treated wood, so if budget is a major concern, you may want to go with wood.

If you can afford it, COMPOSITE.

I have a 27 by 50 ft monster . . . And it was too much money to do in composite, so we did pressure treated wood. Staining was supposed to last 5 years . . . Every two years it needed re-staining . . Like REALLY needed it.

Then we tried this thick "Cover all" type of sealer that is supposed to cover and seal all the splinters . . . This was an expensive 10 YEAR solution that lasted 2 years as well. We followed all the step by step instructions on the container as well. Literally blows off my deck now when I use my leaf blower to clean the deck . . .

Composite, composite composite . . Unless you like to paint.

Have a composite deck - put it in in 2000.  We are really happy with it.  No splinters, discoloration, warping, creaking, etc.  Also easy maintenance - we pressure wash it once every spring to get rid of the winter grime and the stains caused by wet oak leaves and pine needles.  I would never even consider building a deck of wood anymore.