What is meant by coming together federalism and holding together federalism?

Coming together federalism refers to a model where independent states voluntarily unite to form a federal government, often to enhance security or economic stability. This type typically involves a stronger central authority, as seen in the United States. In contrast, holding together federalism occurs when a central government seeks to maintain unity among diverse groups or regions within a country, often to manage ethnic, cultural, or regional differences, exemplified by countries like India. Both models illustrate how federal systems can be structured to address varying political and social challenges.