I read this link [what-is-the-point-behind-unions-in-c](https://stackoverflow.com/questions/15671796/what-is-the-point-behind-unions-in-c)
But this answer doesn't look enough to me.

Can I have more explanations about uses of unions.
I don't want any memory related examples like, this will take max 4 bytes (float occupy 4 bytes ).

```
union un{
    char ch;
    int iNum;
    float fNum;
};

```

So my question is,

**what exactly the use of union?** 

**why we need this?**

Please help me, its confusing me.
Thanks.