data structure

A data structure is a way to organize data so that it can be used effectively. 
Different top level abstract data structure grouped by access method,
* by itself
    * by value
        * 1-1: set
        * 1-n: multiset
    * by priority
    		* general: priority queue
    		* FIFO: queue, 
    		* LIFO: stack
* by another element
    * paired
        * 1-1: dictionary
        * 1-n: mutidictionary
    * chained
        * 1-1: list
        * 1-n: tree
        * n-n: graph