The city, the suburbs, and the rural areas all have schools because students have to go there. This limits the movement of teachers, because they can live in the area where they decide to teach. Most of the trips teachers have to take are field trips. Although teaching seems like a one-way career, it is not. Teachers can become principals, assistant principals, school board directors and superintendents. In addition, teachers receive additional remuneration. As starting salary and average salary show, teachers don't dwell on lower salaries, so as they stay longer at the same school, they get paid more. After 1 to 7 years of stay in the same school, higher level teachers obtain tenure. Tenure is academic freedom with job security in a union contract (A Brief History of Tenure). One of the biggest benefits of teaching is job security and the fact that you'll stay there for a long time.