Answer to the question no 01
ans:
1.Introduction of data structure.
2.Link-list,stack ,queue, tree, graph.
3.Dynamic memory allocation.
4.structure.

Answer to the question no 02

ans: Data structure is the foundation of computer science . it helps to store or organise any information in a computer . It helps computing data Efficiently in a short period of time. This is why Data structure is very important in computer science.

Answer to the question no 03

The real life application of tree, graph ,stack, queue are given bellow;

Tree: We can watch it in gallery or to open different types of folder.
Graph: In different types of location.
stack: plates , submitting home work .
Queue: Buy tickets in ticket counter maintaining line.