The difference between structure and union is that Structure is a client characterized information type in C programming language that consolidates legitimately related information things of various information types together. Association is a client characterized information type, actually like a design. Union joins objects of various sorts and sizes together. The union variable apportions the memory space equivalent to the space to hold the biggest variable of association. It permits changing kinds of objects to have a similar area. The difference between structure and union is that All the design components are put away at adjacent memory areas. The structure type variable can store more than one information thing of differing information types under one name.