Structure vs Union

The difference between a structure and a union are: 

Structure	Union
struct keyword is used to define a structure.	union keyword is used to define a union.
Every member within structure is assigned a unique memory location.	In union, a memory location is shared by all the data members.
It enables you to initialize several members at once.	It enables you to initialize only the first member of union.
The total size of the structure is the sum of the size of every data member.	The total size of the union is the size of the largest data member.
It is mainly used for storing various data types.	It is mainly used for storing one of the many data types that are available.
It occupies space for each and every member written in inner parameters.	It occupies space for a member having the highest size written in inner parameters.
Any member can be retrieved at a time.	One member at a time can be retrieved in the union.