In politics, self-determination is the process of citizens choosing their own government. On a personal level, self-determination is making choices and controlling your own life.
Living with self-determination means deciding (or determining) for yourself and exerting some control over the things you do and the choices you make. This is the original sense of the word, first used in the 1680s. As a political concept, self-determination was popularized by President Woodrow Wilson at the end of the 19th century. It's an accepted idea today in international law that all people have a right to self-determination, freely choosing their leaders.