By Wikipedia 
Freedom of movement, mobility rights or the right to travel is a human rights concept which is respected in the constitutions of numerous states. It asserts that a citizen of a state, in which that citizen is present, generally has the right to leave that state, travel wherever the citizen is welcome, and, with proper documentation, return to that state at any time; and also (of equal or greater importance) to travel to, reside in, and/or work in, any part of the state the citizen wishes without interference from the state. Some immigrants' rights advocates assert that human beings have a fundamental human right to mobility not only across states but across nations. Ray Ybarra, an immigrants rights activist and filmmaker, coined the concept of human mobility to apply to international freedom of movement. According to Ybarra, human mobility is a fundamental human right.
