Guildhalls

There are in most villages in this neighbourhood houses which from time immemorial have been called Guildhalls. These are situate among such small populations that they are manifestly unconnected with trade. Will any of your correspondents tell me— 1st. Why are they called Guildhalls? 2nd. For what purpose were they anciently used? 3rd. Are they common in other counties besides Suffolk? Also: What is the origin of the Friday Streets so common in most villages in this neighbourhood?