In many countries, the government is apportioned according to the level and locality it serves. For example, the state government level serves all those within its state boundaries vis-à-vis the federal government level, which serves all those within the boundaries of the federal government. Because each level has its own laws and statutes, which in no manner or form are meant to contradict each other, a law was instituted that enabled a lower level of government to enact its own laws. This is referred to as the home rule.
The purpose of a home rule is to allow subsets of a government system some degree of autonomous rule. For example, the United Kingdom is composed of England, Scotland, Ireland, and Wales. Each country is given a degree of autonomy to perform government functions that best address the people living within its respective states or jurisdictions. This is because whatever works for England may not necessarily work for Scotland, Ireland, or Wales.
Home rule is also commonly referred to as devolution or independence since constituent parts of a jurisdiction are given the ability to enact laws that address matters concerning the people who live within their jurisdiction.
Home rule is completely different from a federalist government, such as that of the US, since the constituent parts of a federal system are guaranteed constitutional existence. Thus, legislation at any type of level may be created, amended, repealed, reformed, or abolished by any other ordinary type of legislation. Such is the case in the US, Canada, Germany, and Switzerland.