The Bounded Distribution is simply a standard distribution that has additional upper and lower limits set. This prevents extreme or undesirable values being sampled.
If the distribution is sampled and a value outwith the upper and lower range is sampled then the result is not used.
If a value outwith the desirable range is sampled by the distribution then the distribution can be resampled - tick the ReSample check box. If the sample value lies outwith the bounded value and the ReSample option is not ticked then the bounded value becomes the sample value.
The Bounded Distribution can be based upon a standard distribution (e.g. Normal, Exponential, etc) or based on a Named Distribution. Click on the New button and you can create and assign a distribution to set boundaries upon.