Apparently they've streamlined a technique whereby the biological mishmash of understanding is standardized into 'code-like' organization. So instead everyone looking up how to make their own gene of their liking, knowing everything about the whole process from the DNA, to the organism to output, you instead just plug in what you want.
In biology there are known 'promoters' (that say "Start"), terminators ("END"), with the gene in the middle, and a number of other little addons and 'features'. Currently in the lab I have to paste these together on my own, from different sources, using different techniques on each. I have to bring each piece into my local standard before I can put them all together. Because it is MUCH easier to change a few bases, or add/delete, than it is to synthesize de novo entire strands of DNA, there exists a need to have modular, standardized 'code' that can easily be swapped from one project to another. These guys make that easy, I guess. When your goal is not just to change/alter a gene, but to set up a few altered/new/engineered genes (or even an entire pathway) at once, this could save a lot of headache.