A teacher is one who helps students or pupils, often in a school, as well as in a family, religious or community setting. A teacher is an acknowledged guide or helper in processes of learning. A teacher's role may vary between cultures. Academic subjects are emphasized in many societies, but a teacher's duties may include instruction in craftsmanship or vocational training, spirituality, civics, community roles, or life skills. In modern schools and most contemporary occidental societies, where scientific pedagogy is practiced, the teacher is defined as a specialized profession on the same level as many other professions.
In British, Australian, New Zealand, Italian, and some Canadian universities, a tutor is often but not always a postgraduate student or a lecturer assigned to conduct a seminar for undergraduate students, often known as a tutorial. The equivalent of this kind of "tutor" in the United States of America (U.S.) and the rest of Canada is known as a teaching assistant.
In the United States, the term tutor is generally associated with one who gives professional instruction in a given topic or field.
Source: www.wikipedia.org