what is meant by Balance of payment

Balance of payment is the difference between country’s foreign exchange expenditure and its foreign exchange earnings in a given period of time usually a year.

Or

The balance of payments (BOP) is a statement of all transactions made between entities in one country and the rest of the world over a defined period of time.

Or

The balance of payments (BOP) transactions consist of imports and exports of goods, services, and capital, as well as transfer payments, such as foreign aid and remittances in a given period of time.

Or

It is the difference between a country’s foreign exchange earnings from her visible and invisible export and her forex expenditure on visible and invisible imports during certain period of time.