Let's first see what Direct Tax is!
Tax ( Direct Tax ) is a voluntary payment by the residents of a country to the Government of the country in which they are considered as taxable resident for further development and maintenance of the country.
Let's understand it by splitting the above paragraph into few pieces and knowing the meaning of few terms used in it.
1) Voluntary payment - Yes, tax is a voluntary payment. A resident is required to pay tax without any stipulation.
2) Taxable Resident - To pay tax in the country in which such person is considered to be "Taxable Resident". Taxability of a person is based on the number of days he is present in the country which is known as "Residential Status",
if he satisfies the criterias specified for the purpose of Residential Status, he is either said to be a Taxable Resident Or Non-Taxable Resident based on the criterias satisfied.
3) For further development of the country - The ultimate purpose of collecting tax is for the development and maintenance the country such that the Government of the country meets the satisfaction of it's residents on timely basis.
The above is a nutshell of what Income tax is.