Intrinsic Function- A function in a particular language that is handled specifically by the compiler, usually be simply replacing the function call with several lines of code. Because the compiler has responsibility for it, it is often able to optimize the function well.
Matrix- A two dimensional grid of numbers. In computer graphics, typically 4x4 matrices (four rows by four columns) are used. These matrices are often used for transforming points from one coordinate space to another.
Mesh- A collection of connected triangles that usually form a surface or object. Multiple meshes may be contained in a single model.
Normal- A vector that points directly away from a surface, at a given point on the surface. We usually care about the normal at a vertex.
Normalization- The process of converting a vector into one that is pointing in the exact same direction, but has a length of exactly one.
Sprite- A two dimensional image. Sprites can appear in 2D or 3D games and still be called sprites. In a 2D game, these are just the images that you use to draw your game. In a 3D game, these are usually 2D objects that often either rotate to face the camera, or multiple sprites are used so that the player never ends up noticing a 2D flat object in their game.
Texture- Generally, an image that is drawn on the face of an object. It is occasionally used to mean any image.