Question

i cannot understand data structures

Answer 1

*don't -- not can't. And, I don't think I understand them myself.. or at least I don't understand what that term encompasses.

Answer 2

Stack -> first in last out
Queue -> first in first out
Priority Queue -> first in first out unless lower priority
Binary Trees -> Parent node -> left child / right child
Binary Search Trees -> Binary Tree but such that leftchild.key < parent.key, rightchild.key > parent.key
Heaps -> Binary Trees but such that children >= parent
hashmaps -> Stores pairs key : value
Linked Lists -> Node : value + pointer to next node
Double Linked Lists -> Node: value + pointer to next and previous node

Answer 3

What part of data structures is giving you trouble? Do you know what the two word mean by themselves? What is data? What is a structure? I mean in general. Because if we know what these words mean to you then it is easier to realte their computer meaning to you.