A rotation matrix is a mathematical tool used to rotate points in a two-dimensional or three-dimensional space. In two dimensions, a rotation matrix can be represented as a 2x2 matrix, where the angle of rotation is specified. For example, rotating a point by an angle θ involves using the matrix: \[ \beginpmatrix \cos(θ) & -\sin(θ) \\ \sin(θ) & \cos(θ) \endpmatrix \] In three dimensions, rotation matrices become 3x3 and can rotate points around the x, y, or z axes. Each axis has its own specific rotation matrix, allowing for complex movements in 3D space. These matrices are essential in fields like computer graphics, robotics, and physics, where precise orientation and movement are crucial.