What is residency?
Residency is generally divided into two categories: in-state and out-of-state. In-state residents pay in-state tuition rates. Out-of-state residents pay out-of-state rates.
Some institutions have the same rate for each. In most cases though, in-state residents pay a much lower rate than out-of-state residents.
Residency requirements can vary by state, so check the requirements for the state where you plan to attend college.