I imagine you are referring to a dichotomous key is a type of method used by many researchers to identify an organism. Through this kind of key, we can, for example, know the species of plant we are looking at. Just follow the key steps! It is called dichotomous because it allows two inputs. An example of parallel choice in a dichotomous key is the entries "a. Flower color is red; aa. Flower color is blue" that indicate two different response types.
This is 21st century .In this time our society as well as all of the world had become advanced and modern.So,in this time if we started to work without any technology then while working we need more manpower and our time will be loss.Science ,technology,engineering and maths play important role in modern world d .It helps in sustain able development and helps any country to be self dependent and makes profit by which Nations will be developed and it helps to win the future.