N Tyres Application

 Hi every one
 i am new in programming and i am developing my first website
i would like to use N TYRES APPLICATION but i dont no how to make layres and How to call method from one layres to another and how to divid the hole code into different layers
one thing i know is that in bussiness layres we write the logic of our project and in data access layer we write the database code and which is the thired layer i don't know but i think in that layer we set and get the data but i don't know i how to call method in different layer
 please hlep me with some example of each layer 
 
thanks in advance

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