set differently in many countries depending on the number of parties. Parliamentary groups or Caucus Parliamentary groups are groups of some members of the same political party or electoral fusion of parties, also called caucus in the United States Congress and the Parliament of Canada. Technical group A technical group or mixed group is a heterogenous parliamentary group composed of elected officials from political parties of differing ideologies (or independent of any party) who are not numerous enough to form groups on their own. Political group A political group is a group composed of multiple political parties or independents of aligned ideologies. Labour unions A labor union (or trade union) is a political organization formed to promote the interests of workers. Labour unions have various roles in modern politics, including: Organizing strike actions and general strikes Negotiating with employers on behalf of workers Ensuring that workers aren't fired without severance pay Assuring that workers receive reasonable salaries Unlike other political organizations, labor unions do not directly participate in elections, although they may campaign for parties and politicians supporting their positions. Labour unionization is a way for workers to maintain unity and preserve their rights. Often, major corporations antagonize the principle of labor unionization since it results in heavier employment regulations which restrict the powers of big business to fire workers at will, effectively causing economic difficulties for such companies. See also Lobby group International organization Governmental organization References Types of organization