To begin with, software is eating the world. That phrase made famous by Marc Andreessen, points to the problem we are experiencing the computer age.
When you set out to improve your website, you are often driven by a need to refresh what you are seeing. Your site looks old and functions poorly. You can easily compare your site to others and the difference is clear. But beyond all of these responses comes the very principle which should be driving all of our advancement: does it help us to do our business better?
That question is not easily answered unless you are good at understanding how you use technology. I find many businesses do not have the bandwidth to properly ask this kind of question. They rely on professionals to guide them. With that said, there is always ongoing debate about what the task at hand is doing what we need.
Until you can answer that question, the how and the what will escape you.