This question gets asked to determine who can claim you as a dependent. IF someone is your dependent, you get to take their personal exemption on your tax return. A personal exemption means that $4,000 of your income will not be subject to tax. The personal exemption is in addition to the standard deduction.
If you provide more than one half of your own living expenses then you get to take the personal exemption on your tax return. If someone else is paying more than one half of your living expenses, then they can claim you as a dependent if all of the other requirements are met.
This question gets tricky with college student. Parents can claim an exemption for their adult children over 18 (but younger than 24) if they provided more than one half of the student's support. The cost to support a college student is not just room and board expenses while they are at school, but also includes the cost of maintaining the home the student returns to when school is not in session.
See
https://ttlc.intuit.com/questions/2893012-what-does-financially-support-another-person-mean for more information.