non-linear data structureevery data item is attached to several other data items in way that is specific for reflecting relationships the data items are not arranged in sequential structure extreesgraphs notes basic concept of data the memory (also called storage or coreof computer is simply group of bits (switchesat any instant of the computer' operation any particular bit in memory is either or (off or onthe setting or state of bit is called its value and that is the smallest unit of information set of bit values form data some logical properties can be imposed on the data according to the logical properties data can be segregated into different categories each category having unique set of logical properties is known as data type data type are of two types simple data type or elementary item like integercharacter composite data type or group item like arraystructureunion data structures are of two types primitive data structuresdata can be structured at the most primitive levelwhere they are directly operated upon by machine-level instructions at this leveldata may be character or numericand numeric data may consist of integers or real numbers non-primitive data structuresnon-primitive data structures can be classified as arrayslistsand files an array is an ordered set which contains fixed number of objects no deletions or insertions are performed on arrays the size of the array cannot be changed at bestelements may be changed listby contrastis an ordered set consisting of variable number of elements to which insertions and deletions can be madeand on which other operations can be performed when list displays the relationship of adjacency between elementsit is said to be linearotherwise it is said to be non-linear file is typically large list that is stored in the external memory of computer additionallya file may be used as repository for list items (recordsthat are accessed infrequently from real world perspectivevery often we have to deal with structured data items which are related to each other for instancelet us consider the address of an employee we can take address to be one variable of character type or structured into various fieldsas shown belowaddress addresscharacters ( address house no char ( streetchar( citychar( statechar( pinchar( as shown above address is unstructured address data in this form you cannot access individual items from it you can at best refer to the entire address at one time while in the second fromi address you can access and manipulate individual fields of the address house no streetpin etc given hereunder are two instances of the address and address variables lovely professional university