The bank functions as the member of the federal bank which has the capacity to invest the members of its district federal reserve bank. A National bank is synonymous with the central bank.

Description
In simple words, the bank which is controlled by the national government of the country is termed as the national bank.
National bank limited is the private sector fully owned by the company. The term national bank was previously named as the central bank but now it is no more used as the term central bank. It is the major bank found in the country. It is also found in the developing countries. Also, it is present in all independently running estates.
This federally charted bank is the member of the Federal Reserve System. It is the basic pillar that designs the infra structure of the country. It provides support to the financial systems of the country and facilitates the country through their efficient banking system. They control the daily transactions of their local federal reserve bank. The national bank financially supports the country and helps the country in the harsh hours. It also provides service to people and business hence it is the most important part to run a country.