This [post](https://stats.stackexchange.com/a/199312/255062) says

> 
> the beta prior has support over all valid probabilities and only over
>  valid probabilities
> 
> 
> 

About `Support`, [wiki](https://en.wikipedia.org/wiki/Support_(mathematics)) says

> 
> In mathematics, the support of a real-valued function f is the subset
>  of the domain containing those elements which are not mapped to zero.
>  If the domain of f is a topological space, the support of f is instead
>  defined as the smallest closed set containing all points not mapped to
>  zero. This concept is used very widely in mathematical analysis.
> 
> 
> 

What does beta distribution "has support" mean here? Can anyone give an example to illustrate this? Such as this [one](https://stats.stackexchange.com/q/199298/255062)