Heads for the purpose of computation of total income. They are: Salaries, Interest on securities, Income from huse property, Profits and gains of business or profession, Capital Gains, Income from other sources. Each Head has its own separate provisions for the computation of income under that source, Income from all these heads shall be computed separately according to those provisions. Income computed under these heads shall be aggregated, i.e. added together. Each Head has its own deductions, exemptions. This aggregated income shall be adjusted past and present losses if any. This total income is called "Gross Total Income". Out of this total "Gross Total Income", there are certain deductions allowed under Section 80 shall be deducted as per the provisions. After deductions from "Gross Total Income", "Total Income" shall be arrived. On total income, the tax shall be imposed, according to the rate of tax is in force in the previous year upon the assessee. Therefore, it is often called "Incometax is one tax and not the aggregation of taxes under various heads of income". Income tax is only one tax.There are no different income-taxes on different heads.