In the 1970s, Vector based computer graphics was commonly used to display lines, text, and symbols on a CRT. Even though terminals have mostly fallen out of use, the concepts of vector based displays are inherently present in most computer graphics APIs, e.g., DirectX, AutoCad dwg and post-script. The idea is that the designer specifies the line segments to be drawn in the output space [screen], freeing him or her to think about drawing fundamental geometric primitives and turning over the conversion of the vector to a raster image to the API.
A further extension of this idea is think about 3D parts in space and time as well as the feature history and level of detail. A 3D part is oriented in space and its corresponding 2D projection is calculated as a collection of 2D vectors. This leads to the fundamental idea of CAD/CAM. Common CAD/CAM interchange standards are IGES and STEP.