If point move in one direction, we get a line. A line is one-dimensional (length).
When you connect two points, it becomes a line segment
When three or more segment lines meet each other in their end point, it will be formed a Shape.
2D shapes have two dimensions (length and width). Ex: triangles, squares.
When we combine four or more 2D shapes, it will be formed 3D shapes. Ex: cubes, cylinders.