Income tax is a percentage of income paid to the government by the taxpayers for the betterment of the public at large. This income is categorized into different groups on the basis of the amount of income. Each such group is known as a Tax Slab. Tax is charged at different rates on the range of income falling under these different income tax subgroups. The Income Tax Act of 1961 is the law that governs the provisions for our income tax. The income tax rates are usually revised every year during the budget. Various deductions are usually allowed to a taxpayer under Section 80C, Section 80D etc.
If you are resident individual and your total income after all eligible deductions is equal to or less than 5 lakh, then a rebate of Rs. 12500 applies to the total tax payable before 4% health & education cess. If your tax payable before cess is less than Rs. 12500 then that entire amount is discounted.