data structure is nothing but the composition two or more data datatypes .

struct record { int data ; struct record *next };

Datastructure deals not only the location where datas are stored but also provides the relationship between the data.
e.g:
marks scored by a student in five sub..

struct marks

{

char name[20];

int phy che mat bot zoo;

}a;
phy 99
che 98
mat 100
bot 90
zoo 80
the phy che.... are variables.obviously they stored in memory in different locations...from their values we can infer that these variables provides details of marks scored by a student...so the relationship is marks