We are all teachers in one form or another. Our actions may be observed by others and they may come to learn from those actions, for their own application, whether we are intentionally teaching or not.
Learning is largely the option fo the learner and not the imposed lessons of the teacher. The intentional teachers primary function is to set the stage for others to learn.
A static presentation of information to be memorized by students to therefore pass a test is not teaching. Try a to teach an infant to walk with a wonderful Power Point presentation followed up with a test to then walk. They will not have learned a thing and neither do most adolescents and even adults when knowledge is simply offered for testing later.
A key for the purposeful teacher is to engage the learner in the process of learning. We learn by doing in the connection of knowledge, in digestible form, with new experiences in the practice of learning. The students acts upon the stage set for them to their own benefit.
“Learning results from what the student does and thinks and only from what the student does and thinks. The teacher can advance learning only by influencing what the student does to learn.” — Herbert Simon —