A deictic word (it depends on a frame of reference) that indicates what a speaker refers to. It can either point to an object in the physical surroundings, but also to words, phrases and propositions previously mentioned.
That serves to demonstrate, show or prove.
given to or marked by the open expression of emotion; "an affectionate and demonstrative family"
serving to demonstrate
a pronoun that points out an intended referent
given to or marked by the open expression of emotion
