Public law consists of those fields or branches of law in which the state has a direct interest as the sovereign, for example; Constitutional law, Criminal law, Administrative law.
It is concerned with the constitution and functions of the various organs of government, their relations with each other and the citizenry. It asserts state sovereignty. The state is directly interested as a party in public law issues because the modern state is a welfare state hence it endeavors to protect or safeguard public welfare.
Private law: consists of those branches or fields of law in which the state has no direct interest. It is concerned with the legal relations between persons in ordinary transactions.
It deals with the rights and details of parties in ordinary transactions example law of contract, law of property, law of succession, law of marriage, law of trust. Private law is concerned with day to day transactions of legal relationships between persons. It defines the rights and duties of parties