What is Different between internal and international trade?

I take it you mean the difference between "international trade" and "international business". This is really just the difference between "trade" and "business" :- - trade is technically the exchange of good for money or other good. - business is the whole spectrum of dealings in which people and companies engage - it is generally boiled down to the exchange of goods and services for money or other goods or services. So a manufacturer of something is engaged in trade, the lawyers and Accountants who supply that manufacturer their services are engaged in business - and it doesn't matter if it all happens within one country or if it is international - nowadays a company's accounts might well be handled by someone in a different country.