what is importance of decision tree model

Decision trees help to simplify decision making. It also
helps in tracing the steps to develop a solution. Often computer programming is broke
down into a decision tree in order to help facilitate the writing of
code.

it also helps to develop a standard procedure when
running an experiment in the science realm. Does chemical A react with B? If yes proceed
here, if no proceed elsewhere.

One such example from
wikipedia would be, "In the game of "20 Questions", the querent tries to construct a
short binary decision tree that isolates a specific item. The item's identity question
is asked when the current decision tree node is considered reliable by the
querent."