IATA has divided the whole world into three different areas .these areas are called IATA traffic conference area TC 1 /TC2 /TC3. the main reason to divide world into 3 areas is to make the air fare calculation easy and to find out the route of certain journey in safest economical and fastest way.
TC1 consist of North America, Central America, South America, Greenland, Caribbean, Hawaiian Islands panama canal as well as Canada and green land.
TC2 includes the countries of Europe (West of the Urals), Azores, Iceland, Middle East, Africa, Seychelles Islands
TC3 includes the country of Asia (East of the Urals), Oceania, (Australia, New Zealand and South Pacific Islands) ,japan etc and various other island which are in the pacific ocean near the Asia and Australia continents.
Hope this will help as a quick reference for new comer in the industries to have a quick check which rate and surcharges such as fuel and security tariff to be applied .