Are you looking to create a place to entertain and socialise? An area where your children can play without getting dirty? Or do you want decking for your hot tub or pool?
Knowing what you want to use your decking for will determine everything from location to what type of deck boards you should choose. In composite decking boards, you can have hollow and solid options. For areas with a hot tub solid boards with a substantial base will be required, as well as areas with heavy footfall such as pubs.
For areas which will have light use, such as a garden decking area, hollow boards may be suitable and thus a slightly cheaper option.