The Chamber (short for the Regional Parliament Chamber) is basically the proper name for a parliament building representing a different Tract (region) of Elejamie. Once an issue arises, the members of each Chamber (if it's a nationwide issue) or the members of a specific Chamber (if it concerns one Tract) hold a vote on it to see whether or not it should go to the Select Council. Once they've had their say on it, they will hold a vote to see what course of action they should take (by either going with one option or dismissing it altogether).
It is a common belief that the "The Interim Government", who governed the country whilst TSC were on hiatus, was the Select Council operating under a different name. Although they were chosen by the Select Council themselves in order to temporarily succeed them, The Interim Government couldn't have any of its members voted out by the general populace (although members could be ejected by the rest of The Interim and thus a replacement could be voted in. The same went if a candidate dies or any other method preventing them from working. To avoid loopholes, candidates were pre-chosen and voted in by the people).