A teacher (also called a school teacher or, in some contexts, an educator) is a person who helps students to acquire knowledge, competence or virtue. Informally the role of teacher may be taken on by anyone (e.g. when showing a colleague how to perform a specific task).
Being a professional teacher means being knowledgeable and enthusiastic about one's materials, creating a supportive and respectful classroom environment, building authentic relationships with and advocating for students, being organized and planning ahead, remaining open to new ideas and continuing to learn, appreciating diversity, and making complicated subject matter engaging and understandable for students