Data: data are simply values or set of values. A data item refers to a single unit of value. Data item divided into subitems are called group items. Items that are not in group are called elementary items. For example: An employ name is a data item but you may divide into three subitem: first name, middle name and last name. Difference between data and information:

- Data is something like raw material.
- When we process data and it start giving some meaning than it becomes information.

For example: Data:

Information:

Data Structures: Storing and organizing the data in such a way that it becomes easier to access and modify when needed is called data structure.

The only way to storing and organizing data in a way we have discussed above is storing the data into some logical manner mathematical manners. So according to the above explanation we can say... A logical or mathematical model which allow us to organize data into some particular organization. Classification of Data Structures:

- Linear data structure
Non-linear data structures.

Linear Data structures: The data structure in which all of its items are stored in or lets say arranged in linear order.

Non-Linear Data structure: There is no sequence in these kind of data structures arrangement. The items in these kind of data structure are arranged in connections with other items. Let say one item of this data structure type will be connected with two or more items.

Linear DS:

- Arrays
- Stack
- Queues
- Linked-list

Non-Linear Data Structures

- Tress
- Graphs