Short answers, pulled from the story.
The Rockingham Whigs were the first modern political party to retain a coherent label and motivating principles while out of power. This group emerged in the 18th century to challenge the absolute rule of the monarchy and structured disputes in the politics of the United Kingdom throughout that century.
The modern political party system in the United States took root during the 1700s when groups began to function as stable institutions rather than temporary alliances. The First Party System emerged from political controversies in the early 1790s over the extent of federal government powers.
Economists and political scientists had shown by the 1950s that party organizations could take advantage of the distribution of voters' preferences over political issues. The theory that parties are produced by social cleavages suggests that society is divided in a certain way and a party is formed to organize that division into the electoral competition.
Political scientists have distinguished between elite parties, mass parties, catch-all parties, cartel parties, and niche parties. Elite parties were political elites that were concerned with contesting elections and restricted the influence of outsiders, while mass parties are funded by their members and rely on and maintain a large membership base.
Political parties acquire funds through dues-paying party members, advocacy groups and lobbying organizations, corporations, trade unions, and candidates who may self-fund activities. Governments also provide some level of funding for political parties, and nearly all of the 180 countries examined by the International Institute for Democracy and Electoral Assistance have some form of public funding for political parties.
Nearly all political parties associate themselves with specific colours and symbols primarily to aid voters in identifying, recognizing, and remembering the party. This branding is particularly important in polities where much of the population may be illiterate, so that someone who cannot read a party's name on a ballot can instead identify that party by colour or logo.