The term "teaching media" originally only refers to the teaching machine that appeared in the United States in the 1960s. Now, it refers to "any means of spreading knowledge", including printed materials such as teaching materials and teaching reference materials, as well as audio-visual auxiliary equipment such as models, pictures, slides, tape recorders, video recorders, movies and televisions.

There are many different classification methods for teaching media. The Encyclopedia of American Education divides teaching media into four types: (1) printed materials, such as books, magazines and pamphlets. (2) Graphic media, including charts, maps, bulletin board displays and projectors; (3) Photographic media such as photos, slides and movies; (4) Electronic media, including audio and video recording equipment. Some people also divide teaching media into five categories, such as "Teaching and Media" by Cholach, and divide teaching media into: (1) things and people; (2) projecting visual materials; (3) auditory materials; (4) printed materials; (5) Presentation materials.

According to the sensory channels of teaching media, we divide teaching media other than textbooks into the following four categories: (1) non-projection visual teaching AIDS, including blackboards, models, objects, etc. (2) Projection vision auxiliary equipment, including slide projector, projector and its auxiliary equipment; (3) hearing AIDS, such as tape recorders, players, radios, etc. ; (4) Audio-visual AIDS, including movies, television and videos.