Projection means extending something outward or forward. When a rock juts out from a cliff face, that ledge is a projection. When a teacher uses a projector to display images on a screen, the machine sends light forward, projecting the image across the room. Weather forecasters make projections about next week's temperatures, extending current patterns forward in time to predict what might happen.

In mathematics, projection often means showing a three-dimensional object as a flat, two-dimensional image, like how a globe gets projected onto a flat map. Architects create projections of buildings, showing how they'll look from different angles.

The word also describes a psychological pattern where people attribute their own feelings or faults to others. If someone feels nervous but won't admit it, they might accuse everyone else of being anxious. That's projection: seeing your own traits projected onto other people.

In all these uses, something internal or hidden gets cast outward: a rock face extends into space, an image travels through air onto a wall, a current trend extends into future possibilities, or inner feelings get placed onto someone else.