A filmstrip was a teaching tool used in classrooms from the 1940s through the 1980s, before videos and computers became common. It consisted of a long strip of transparent film, like a ribbon of photographs, with images printed on it in sequence. Teachers would load the filmstrip into a special projector that shone light through one frame at a time, displaying the image on a screen or wall at the front of the classroom.

Each frame showed a picture, diagram, or text, and the teacher would advance the filmstrip manually, frame by frame, while explaining the lesson. Many filmstrips came with an audio recording on a record or cassette tape that narrated the story or lesson, with a beep sound telling the teacher when to advance to the next frame. Students would sit in a darkened classroom, watching filmstrips about everything from science experiments to historical events to stories and adventures.

Filmstrips have mostly disappeared now, replaced by videos and digital presentations, but many adults remember the distinctive clicking sound of the projector and those beeping audio cues as a memorable part of their school days.