A more thorough explanation:

Personal law refers to the laws that govern a person's family matters, regardless of where they go. In common-law systems, personal law is based on the law of the person's domicile, while in civil-law systems, it is based on the law of the individual's nationality, also known as lex patriae.

Examples of personal law include laws related to marriage, divorce, legitimacy, capacity, and succession. For instance, if a person is a citizen of India, their personal law would be based on Indian laws, even if they are living in another country.

The concept of personal law is based on the idea that people are social beings, and their daily transactions that affect them personally should be governed by the most suitable and adequate system of law. Although the law of the domicile is the primary criterion for personal law in common-law systems, any person of full age and capacity can establish their domicile in any country they choose, making the law of that country their personal law.