A lesson plan is a teacher's daily guide that outlines what students need to learn, how it will be taught, and how learning will be measured. Lesson planning refers to a set of teaching acts or events planned to generate a learning environment for students. A well-developed lesson plan reflects the interests and needs of students. Lesson plans originated from gestalt psychology, which influenced how humans learn. In schools, students perceive the whole through parts, and units play an important role in learning by being divided into lessons by teachers.