What is venn diagram represents?

Answer 1

Venn diagrams are used to visually represent sets, subsets and which sets or subsets form unions and intersections. For example if there are N employees in a department comprising men, women, smokers, non-smokers, vegetarians, non-vegetarians, then N is the total set and within that there are subsets for example

1) Men who smoke and are vegetarins

2) Women who don't smoke and are non-vegetarians

3) .....

4) so on

Venn diagrams (usually using circles) can depict pictorially how these subsets relate to the main set and other subsets. Once this picture is clealy drawn and understood further mathematical analysis becomes easy.