The subject of Islam has many branches and aspects to it - making it a discussion that starts and never ends. This is due to Islam containing the details and rulings pertaining to everything.
There is not a single matter - small or great - from the matters of belief, action, legislation, or etiquette, that Islam did not make mention of. Rather it encompassed all matters; either generally or specifically - whether in relation to the nation in its entirety, or those affairs that concern a person specifically.