Plants roots need 3 things, water/moisture, nutrients, and oxygen. What makes types of hydroponic systems different is simply how they deliver these three things to the plants roots.
It’s important to first consider the type of plants you want to grow in it, as well as the space you have to grow them in. Then you’ll want to make sure to design the system to be able to accommodate the plants needs (plant size, root size, oxygen to the roots, water consumption, etc. etc.) even after they reach full size. While one type of hydroponic system may be well suited for growing some types of plants, it may not be the best choice for growing others.
Some basic things that you want to keep in mind when designing and building (even buying) any hydroponic system are; First, you will probably want to use it more than once, so you should think about things like how hard it will be to break it down and take it apart to clean it thoroughly between plantings. Also, should you have a problem while the plants are still growing, you should think about how hard will it be to fix the problems without doing damage to the plants or system.