What do you mean by rank and income of country i need easy meanings of rank and easy meanings of income i am unable to understand the meaning of rank of country and income so plz explain me in easy vocabulary so i can understand easily

Dear Student 
Rank of country is the position of the country. It can be based on area, population etc.,
Example: In population India has second rank.

Income of a country is the money recieved from various sources. Example for source is tax.

Regards