what is an assessment year?

An assessment year is a year in which tax on income earned during the previous year is paid.

Income tax

Who is an assessee?

Assessee is a person who is in a position to pay tax to the government. 

Income Tax-1

What is the base for imposing Income tax?

The base for imposing income tax is " Residential Status " (i.e., how many days an assessee has stayed in India during the current previous year)