1. The term "scale factor" typically refers to the ratio by which a figure is enlarged or reduced in size in geometry. 2. It is the multiplier used to increase or decrease the dimensions of a shape while preserving its proportions. 3. For example, if a shape is scaled by a factor of $k$, then every length in the shape is multiplied by $k$. 4. If $k > 1$, the shape enlarges; if $0 < k < 1$, the shape reduces. 5. The scale factor can be found by dividing a length in the image by the corresponding length in the original figure. 6. In algebra, scale factor can also refer to the constant multiplier in functions like $y = kx$ which stretches or compresses the graph vertically. 7. To summarize, the scale factor is a number that scales, or multiplies, the size of an object or function.