The degraded, often crude and vulgar, language spoken by members of a subculture or “people of the streets”. It differs from the widely spoken language from the point of view of articulation, intonation, selection of certain standard expressions and preference of very lower-class words.

It is the mental process that a person goes through not only in order to acquire knowledge and skills but at the same time, under the guidance of the teacher, to become aware of the process required in order to acquire knowledge and skills outside the classroom.

To acquire knowledge and skills through the conscious or subconscious use of one’s mental abilities.

Α part/unit of the learning process that can be either written (in a book or elsewhere) or oral with the presence of a teacher who introduces a subject/topic, presents it in a complete manner, explains it and asks students to learn it.

The mental process of acquiring knowledge and skills but also the product or result of this process.