Any AI(Artificial Intelligence ) technologies whether it is Neural Network , Fuzzy logic etc are attempts to simulate human brain (thats the reason it is called AI).
You know the importance of experience in human life same is applicable in AI as well. How it works ,
First you design your system and then train that system using past data . And then if same kind of situation(or you can assign weight or many other things) appears in future your system will take it own decision. So your system would be as good as you train that. More past data then more accurate system.
For an analogy , look we entered market recently and still trying to learn but we have learn few conditions , ex . if Dow is down then high chance that Nifty will go down , or If FII put money and DII also put then market will go up or if net cash input is positive then market will go up or if there is any bad news market will go down or if reliance rise by 5% then market will rise by 2% (?) ...you can use these conditions to design your system with past data.
another example:Now if we consider Savant Sir brain as a system(I, not AI) , and our brain as a system then we will undoubtedly say that savant sir brain(system) is much more efficient than ours because it has been trained with more data (market exp) to understand market than ours brain or system.
I consider it much fancy technology and system . Why to use AI if we have I . One application of this technology is in flight Auto pilot.