At a Glance
teacher
A teacher writing on a chalkboard.
teaching
teaching, the profession of those who give instruction, especially in an elementary school or a secondary school or in a university. Measured in terms of its members, teaching is the worldâs largest profession. In the 21st century it was estimated that there were about 80 million teachers throughout the world. Though their roles and functions vary from country to country, the variations among teachers are generally greater within a country than they are between countries....