MVP matrix (model-view-projection)
The combined model-view-projection matrix that turns a vertex's local coordinates into screen space in a single multiply — the backbone of every vertex shader.
Three transforms stack to put a 3D vertex on screen: the model matrix places an object in the world, the view matrix moves the world relative to the camera, and the projection matrix applies perspective (or orthographic) foreshortening. Multiplied together they become one matrix, and the vertex shader does a single matrix-vector product per vertex. Pre-combining on the CPU saves the GPU two multiplies per vertex across millions of them.
The output lands in clip space; the hardware then divides by w to reach normalized device coordinates. Column-major (OpenGL) versus row-major (Direct3D) conventions are a perennial source of transposed-matrix bugs.